UNIVERSITY    OF    CALIFORNIA    PUBLICATIONS. 


University  of  California— College  of  Agriculture, 


AGRICULTURAL  EXPERIMENT  STATION. 


E.  W.  HILGARD,  Director. 


CITRUS  FETJIT  CULTURE 


By  J.  W.  MILLS. 


A  CITRUS  FRUIT  REGION  IN  SOUTHERN  CALIFORNIA. 

BULLETIN    No.   138. 

(Berkeley,  January,  1902.) 


SACRAMENTO: 
a.  j.  Johnston,  :::::::  superintendent  state  printing. 

1902. 


rp 


TABLE  OF  CONTENTS. 


PREFATORY  NOTE  BY  C.  H.  SHINN 3 

VARIETIES  OF  ORANGES 5 

Washington  Navel 5 

Thompson's  Improved 5 

Golden  Nugget  Navel 6 

Golden  Buckeye  Navel _ 6 

Navelencia 7 

Valencia  Late 7 

Redlands  Early  Orange 8 

Seedlings ... 8 

Blood  Oranges _ 8 

Mediterranean  Sweet _._ 9 

St.  Michael  Paper-Rind _.  9 

Miscellaneous  Varieties _. 9 

THE  STOCK  FOR  CITRUS  FRUITS 10 

Sweet-Stock  Root-System _ 11 

Advantages  of  Pomelo  Stock 12 

The  Florida  Sour  Orange 15 

Conclusions  Respecting  Stocks 19 

METHODS  OF  PLANTING  ORCHARDS _ 19 

The  Ordinary  Transplanting  Method _ 20 

The  Reed  System  of  Transplanting 20 

The  Post-hole  Method ..   23 

WORKING-OVER  OLD  ORCHARDS 24 

Method  of  Re-hudding  Trees _ 24 

Value  of  Cured  Buds... 25 

Placing  the  Bud. _ 25 

When  to  Remove  the  Bands 26 

Removal  of  the  Tops 26 

PRUNING  AND  SHAPING  TREES 32 

Pruning  Bearing  Trees 32 

Renewal  of  Tops - , - 32 

CULTIVATION  AND  IRRIGATION _ 33 

The  "  Irrigation  Hardpan" ._ ...  34 

Value  of  Proper  Deep  Cultivation 35 

Reckless  Deep  Cultivation _ 36 

Practical  Notes  on  Deep  Cultivation  and  Irrigation 36 

Waste  from  Evaporation  of  Water 37 

Spread  of  Water  from  Deep  Furrows 37 

NOTES  ON  DISEASES  OF  THE  ORANGE _ 39 

Gum  Disease - ---  39 

Antiseptic  Washes  for  Gummosis 39 

Value  of  Sour-Orange  and  Pomelo  Stocks.. 40 

The  Die-back  Trouble 40 

Mottled  Leaf -- 41 

Difficulty  of  Replacing  Trees. 42 

CALIFORNIA  ORANGE  AND  LEMON  STANDARDS 42 


PREFATORY  NOTE. 


By  CHARLES  H.  SHINN,  Inspector  of  Stations. 


The  University  of  California  Experiment  Station  has  been  testing 
citrus  fruits  for  many  years,  beginning  at  the  Central  station  (where 
soil  and  climate  are  very  ill-adapted  to  these  fruits)  and  continuing  at 
the  substations  as  fast  as  they  were  established.  The  results  of  this 
work,  to  some  extent  printed  in  annual  reports,  have  been  mainly 
obtained,  as  was  to  be  expected,  in  Southern  California,  the  best  sub- 
station for  this  work  being  situated  there,  in  the  Chino  Valley.  At 
other  substations,  however,  some  useful  results  have  been  reached,  which 
may  be  briefly  stated. 

At  the  Sierra  Foothill  substation,  Amador  County,  three  varieties  of 
oranges — Konah,  Malta  Blood,  and  Washington  Navel — on  sweet-stock, 
were  planted  in  1888.  Florida  sour-stock  seedlings  were  put  in  later- 
then  some  hardy  Japanese  stocks  (Citrus  trifoliata).  The  soil  where  the 
first  planting  was  done  was  poor  and  rocky,  and  the  trees  were  several 
times  badly  frosted,  so  that  by  1896  this  trial  was  considered  a  failure 
only  the  Japanese  long-fruited  "  Cumquat,"  or  gooseberry  orange,  and 
the  dwarf  Oonshiu  (both  on  trifoliata  stock)  having  succeeded.  These, 
however,  have  done  so  well  that  their  culture  is  strongly  recommended 
for  gardens  at  this  elevation  (about  2,000  feet)  in  the  Sierra  foothills. 
For  standards  the  sour-stock  appeared  to  be  decidedly  hardier,  and  in 
every  way  better  than  the  sweet-stock.  A  new  and  more  sheltered 
location  was  chosen  on  better  soil,  and  here  a  small  orange  grove  has 
been  established,  with  every  prospect  of  success. 

Oranges  were  also  planted  at  the  San  Joaquin  Valley  substation,  near 
Tulare,  and  at  the  Southern  Coast  Range  substation,  near  Paso  Robles. 
At  the  latter  point  they  utterly  failed,  both  soil  and  climate  proving 
totally  unsuitable  for  semi-tropic  trees;  this  fact  was  therefore  pub- 
lished, and  no  further  experiments  made.  At  the  former  point,  Tulare 
some  of  the  orange  trees  have  grown,  though  often  heavily  cut  back  by 
frost.  The  sour-stock  proves  most  resistant  to  alkali,  and  as  a  rule 
hardier.  The  dwarf  deciduous  orange  of  Japan  (Citrus  trifoliata)  grows 
and  fruits  in  even  stronger  alkali,  and  therefore  is  recommended  as  a 
stock  for  gardeners  in  such  localities. 

The  planting  of  citrus  fruits  at  the  Southern  California  substation 
began  in  the  spring  of  1891,  when  the  foreman  set  out  eight  varieties  of 
orange,  then  three  years  from  bud,  on  sour-stock,  and  eight  varieties  on 
sweet-stock;  also  three  varieties  of  citron  and  three  of  lemon,  all  on 
sweet-orange  stock.  The  tract  was  well  situated,  though  far  from  the 
hills,  and  on  lower  ground  than  the  best  conditions  require.  Additions 
were  made  to  the  orchard  each  following  year,  and  by  1896  about 
twenty-five  varieties  of  citrus  fruits  were  in  bearing.  At  the  present 
time,  the  orchard  includes  every  variety  of  promise  which  can  be 
obtained  in  California  or  from  the  Department  of  Agriculture  at  Wash- 


—  4  — 

ington,  besides  local  seedlings  under  trial.  Some  kinds  have  been  dis- 
carded and  trees  regrafted.  The  orchard  is  well  kept,  healthy,  and  free 
from  insect  pests;  it  constitutes  a  good  working  model  for  an  orange 
grove  under  valley  conditions.  A  part  of  the  illustrations  which 
accompany  this  bulletin  are  from  this  orchard. 

But  the  culture  of  citrus  fruits  has  become  the  leading  industry  of 
many  districts  of  California,  and  it  is  being  developed  with  surprising 
skill  and  energy  by  very  capable  horticulturists,  some  of  whom  have 
been  almost  a  lifetime  in  this  occupation.  It  is  therefore  essential  to 
the  truthfulness  of  any  inquiry  into  the  present  problems  of  citrus-fruit 
culture  that  a  wider  range  of  observation  than  that  afforded  by  the  sub- 
station tract  of  thirty  acres  should  be  taken.  Mr.  J.  W.  Mills,  foreman 
of  this  substation  since  1893,  was  therefore  sent  out  to  visit  some  of  the 
best  orchards  in  leading  orange  districts  of  Los  Angeles,  San  Bernardino, 
and  Riverside  counties,  and  to  compare  the  station  experience  with  that 
of  successful  commercial  growers.  The  results  should  possess  interest 
for  those  who  wish  to  plant  citrus  fruits  in  any  part  of  California,  since 
the  conditions  of  soil  and  climate  at  Cloverdale,  Calistoga,  Palermo, 
Porterville,  and  other  northern  and  central  orange-growing  points, 
while  in  some  respects  quite  different  from  those  of  the  southern  orange- 
growing  counties,  are  sufficiently  similar  to  make  careful  observations 
in  any  part  of  California  valuable.  Much  more  complete  studies  of 
local  conditions  have  been  made  in  the  southern  citrus  districts  than 
in  other  parts  of  the  State,  and  some  of  the  conclusions  herein  reached 
may  need  modification  as  respects  northern  districts  when  an  equal 
amount  of  local  experience  shall  have  been  there  accumulated. 

In  citrus  fruit  districts  the  high  price  of  land  that  is  known  to  be  well 
situated,  of  the  best  quality,  and  supplied  with  water,  leads  men  to 
extend  citrus  culture  far  beyond  its  natural  limits,  upon  unsuitable 
soils  and  into  frosty  localities.  The  marked  recent  advance  in  average 
prices  of  citrus  fruits  and  of  well-planted  orchards  has  also  caused 
hasty  and  careless  planting,  even  in  well-established  districts.  Many 
old  trees  are  bearing  less  satisfactory  crops  than  heretofore,  and  various 
plant  diseases  add  to  the  anxiety  of  the  orchardists.  Technical  knowl- 
edge and  a  high  degree  of  horticultural  skill  are  every  year  more 
essential  to  the  prosperity  of  each  individual  orange-grower. 

The  observations  of  many  successful  citrus-fruit  orchardists  have 
been  placed  at  the  service  of  the  station  in  preparing  this  bulletin, 
partly  in  obtaining  the  history  of  the  older  groves  and  of  the  origin  of 
some  new  varieties,  partly  in  securing  needful  details  respecting  more 
recent  practice  in  planting  and  culture  on  a  commercial  scale,  in  repre- 
sentative districts.  Credit  has  been  given  in  all  cases  for  such  assistance,, 
without  which  this  bulletin  would  have  been  merely  a  record  of  experi- 
ments in  one  orchard.  The  discussion  is  almost  wholly  devoted  to- 
problems  of  orange  culture,  but  some  references  are  made  to  the  lemon. 

The  following  pages  have  been  condensed  and  edited  from  the  manu- 
script furnished  by  Mr.  J.  W.  Mills,  foreman  of  the  substation.  All 
the  illustrations  are  from  photographs  taken  by  Mr.  Mills. 


CITRUS  FRUIT  CULTURE. 


Varieties,  Stock,  Planting  From  Nursery,  Re-budding  Old  Orchards, 

Cultivation,  Irrigation,  Diseases,  Remedies, 

and  Other  Practical  Problems. 


By  J.  W.  MILLS. 


VARIETIES  OF  ORANGES. 

The  Washington  Navel,  which  is  so  well  known  that  it  hardly  needs 
especial  description,  is  still  the  only  orange  that  the  market  demands 
in  large  quantities.  There  are,  however,  several  sub-varieties  of  the  fruit, 
none  of  which,  so  far  as  tested  commercially,  surpass  the  best  of  the 
original  type.  The  quality  of  this  orange  varies  according  to  soil  and 
location.  Its  fortunate  tendency  to  sport  gives  promise  of  ultimate 
improvement  over  the  original  type,  and  several  new  varieties  of  Navel 
oranges  have  been  selected  and  are  being  introduced. 

Thompson's  Improved  Navel. — The  first  important  variation  from  the 
Navel  was  ''Thompson's  Improved,"  introduced  by  Mr.  A.  C.  Thomp- 
son, of  Duarte,  Los  Angeles  County.  The  introducer  claims  that  this 
variety  is  not  a  sport,  but  is  a  special  creation  of  his  own,  accomplished 
by  the  division  and  union  of  buds  of  select  Navel,  St.  Michael,  and 
Blood  oranges.  (See  Mr.  Thompson's  note  on  his  Navelencia  orange, 
page  7.)  The  practical  difficulties  in  such  division  and  union  are  so 
great  that  many  more  experiments  along  this  line  are  necessary  to  con- 
firm or  disprove  Mr.  Thompson's  claim  of  the  origin  of  this  variety.  It 
is  a  beautiful  fruit,  which  has  been  eagerly  sought  after  and  widely 
planted.  There  are  conflicting  opinions  as  to  its  value  as  a  shipping 
variety  in  different  sections  of  the  southern  citrus  belt.  Mr.  C.  C. 
Buffington,  of  Corona,  an  extensive  buyer  and  shipper  of  citrus  fruits, 
says:  "There  has  always  been  a  doubt  in  my  mind  as  to  its  being  a 
practical  variety,  owing  to  its  thin  skin  and  tender  pulp." 


Mr.  H.  D.  Briggs,  of  Azusa,  writes  :  "My  five  years'  experience  is  that 
I  consider  the  Thompson  superior  to  the  Washington  Navel,  for  the 
following  reasons :  It  has  a  smoother  skin ;  it  has  a  thinner  skin ;  it  is 
higher  colored ;  it  is  a  heavier  bearer  at  the  same  age ;  the  tree  is  a 
little  larger  and  more  upright  at  the  same  age ;  it  stands  shipping 
fully  as  well.  The  only  fault  I  have  to  find  with  it  is  that  it  dropped 
far  heavier  last  spring,  but  still  the  trees  have  twice  the  number  of 
oranges  left  that  the  Washington  Navels  of  the  same  age  have.  The 
soil  is  a  rich,  sandy  loam  that  is  predisposed  to  grow  a  large,  rather 
coarse  Washington  Navel." 

The  fruit  of  the  Thompson's  Improved  Navel  as  grown  at  the  Pomona 
substation  does  not  seem  equal  to  the  best  type  of  Washington  Navel. 
This  may  be  due  to  its  thinner  skin,  which  is  more  injured  by  the  frost. 
A  temperature  of  25°  Fahr.  is  almost  sure  to  be  reached  some  time 
before  the  fruit  is  fully  ripe,  and  this  will  usually  injure  a  thin-skinned 
early  or  mid-season  orange  where  a  thick-skinned  one  would  be  but 
slightly  injured.  The  Thompson's  Improved,  therefore,  is  not  recom- 
mended for  planting  in  locations  that  are  frequently  subject  to  severe 
frost. 

The  thin  skin  of  Thompson's  Improved  Navel  does  not  necessarily 
detract  from  its  shipping  qualities,  but  there  may  be  other  qualities  that 
make  it  a  poor  shipper,  such  as  a  loose  attachment  of  the  divisions  of 
the  fruit.  The  St.  Michael  Paper-Rind  has  a  much  thinner  skin  and  is 
an  excellent  shipper. 

Golden  Nugget  Navel. — This  sub-variety  is  a  new,  early  kind  that  was 
found  to  be  sweet  and  juicy  on  the  20th  of  November,  at  Glendora, 
Los  Angeles  County.  There  is  but  one  tree  of  full-bearing  age,  and  it  is 
in  a  favorable  locality  for  early  ripening.  Mr.  J.  P.  Englehardt,  of 
Glendora,  in  whose  orchard  it  stands,  writes  as  follows  :  "The  tree  was 
purchased  among  a  lot  of  nursery  stock  at  Alhambra,  ten  years  ago. 
It  looked  like  all  the  rest,  but  it  would  not  grow,  and  was  stunted  in  the 
first  place.  I  cut  it  back  to  almost  nothing,  when  it  put  forth  leaves  of 
a  different  appearance,  and  subsequently  bore  fruit  that  differed  from 
the  others." 

Mr.  R.  M.  Teague,  of  San  Dimas,  who  is  propagating  this  variety, 
says:  "This  orange  ripens  very  early  in  the  season,  and  is  a  very  thin- 
skinned,  nice-appearing  fruit.  There  being  only  one  tree  in  fruit,  it  is 
hard  to  state  just  what  the  average  time  of  ripening  will  be;  all  we  can 
say  is  that  it  is  very  early." 

Golden  Buckeye  Navel. — This  sub-variety  is  reported  to  be  a  sport 
from  the  Washington  Navel.     The  rind  is  as  thin  as  that  of  the  Tan- 


—  7  — 

gerine,  but,  unlike  the  latter,  it  adheres  so  closely  to  the  pericarp  that 
the  divisions  can  be  plainly  seen  through  it  after  the  fruit  has  been 
picked  a  few  days,  giving  it  the  appearance  of  a  nutmeg  melon.  Upon 
inquiry,  Mr.  Teague,  of  San  Dimas,  writes:  "The  orange  tree  you  men- 
tion as  growing  in  Pomona  originally  came  from  here;  there  happened 
to  be  one  branch  that  ' sported'  to  this  in  the  twenty-acre  grove  here  at 
San  Dimas.  These  oranges  ripen  very  early,  are  very  thin-skinned, 
with  a  slight  pineapple  flavor,  and  all  pack  as  'fancies.'  The  only 
objection  to  this  orange  is  the  color  of  its  skin,  which  is  a  pale  yellow, 
and  so  it  seems  to  be  a  cross  between  a  Washington  Navel  and  a 
St.  Michael." 

Navelencia. — This  orange  is  a  recent  introduction  of  Mr.  A.  C.  Thomp- 
son, of  Duarte,  the  originator  of  Thompson's  Improved.  Some  growers 
say  that  trees  of  the  Navelencia  grown  by  them  compare  favorably  in 
size,  when  three  years  old,  with  five-year-old  Thompson's  Improved, 
when  both  are  grown  under  the  same  conditions.  The  Navelencia  tree 
is  a  more  upright  grower  than  the  original  Washington  Navel.  When 
Thompson's  Improved  is  sweet  enough  to  be  pleasant  to  eat,  Navelencia 
is  still  unfit  to  eat.  While  its  lateness  and  other  desirable  qualities 
will  probably  give  it  a  place  with  citrus-growers,  it  is  not  likely  that  it 
will  hang  on  the  tree  and  retain  its  good  qualities  as  long  as  the  true 
Valencia.* 

Valencia  Late. — The  Valencia  orange  ripens  during  May  and  June, 
and  commercially  stands  next  to  the  Washington  Navel.  It  will,  per- 
haps, never  be  shipped  as  extensively,  because  it  comes  in  at  the  end  of 
the  orange  season  when  early  deciduous  fruits  are  in  market.  But  this 
variety  has  the  additional  advantage  of  keeping  well  when  left  all  sum- 
mer on  the  tree,  and  can  thus  be  held  over  for  the  early  winter  and 
holiday  trade.     Early  new  varieties  will  probably,  in  time,  take  its  place 


*Mr.  Thompson's  account  of  the  origin  of  this  variety  is  given  by  himself  as  follows : 
"  The  Navelencia  is  an  equal  production  of  one  half  Valencia  and  the  other  half  Thomp- 
son's Improved  Navel  orange.  In  1890  I  made  several  crosses,  but  this  was  the  only 
one  that  made  a  complete  union.  In  many  cases  one  of  the  buds  so  spliced  together 
would  start  several  days  before  the  other  made  a  move,  so  both  germs  grew  separate; 
in  some  cases  one  half  died,  in  others  both  barks  would  unite,  but  only  one  germ  would 
start;  this  one  seemed  to  grow,  both  germs  uniting,  both  barks  catching  quickly,  and 
made  one  shoot.  This  operation  has  to  be  watched  every  day  with  a  powerful  glass 
after  the  fifteenth  day  from  the  time  the  buds  are  inserted  in  the  young  trees  in  the 
nursery,  to  make  sure  that  both  germs  have  united ;  the  half  buds  must  be  of  equal  size 
and  age,  and  of  equal  ripeness,  and  concave  on  the  germ  edges  to  fit  the  convexity  of 
the  tree,  when  held  tightly  together.  Wax  over  lightly  after  pressing  them  close  to  the 
tree,  covering  the  whole  cut  with  wax  cloth  for  fifteen  days,  then  begin  examining  as  to 
the  progress,  re-wrapping  every  time  until  you  are  satisfied  that  the  experiment  is  a 


—  8  — 

for  this  purpose,  as  it  assumes  a  greenish  color  when  left  on  the  tree 
after  its  natural  period  of  maturity. 

In  regard  to  the  prospects  for  future  plantings  of  the  Valencia  Late, 
Mr.  A.  H.  Naftzger,  president  and  manager  of  the  Southern  California 
Fruit  Exchange,  writes  as  follows:  u  Since  they  come  at  a  time  when 
the  demand  for  oranges  is,  in  the  nature  of  things,  limited,  I  doubt  if  a 
larger  acreage  than  is  now  coming  forward  in  California  gives  good 
promise  of  satisfactory  results." 

Redlands  Early  Orange. — This  is  an  early  seedling  found  in  a  nursery 
row,  and  now  being  tested  by  Mr.  H.  H.  Smith,  of  Redlands.  It  ripens 
for  the  Thanksgiving  trade,  at  which  time  it  has  high  color,  and  is  very 
sweet,  but  thought  by  some  growers  to  lack  in  flavor.  Samples  exhib- 
ited at  the  Farmers'  Club  Institute  held  at  Riverside  December  20, 1900, 
were  fully  matured  and  more  palatable  than  any  other  variety  shown 
at  that  time.  The  oranges  are  small,  averaging  250  or  even  more  to 
the  box. 

Seedlings. — While  no  one  now  thinks  of  planting  seedlings,  yet  some 
of  the  best  paying  groves  are  composed  of  these,  as  the  immense  size 
that  the  trees  attain  at  the  age  of  fifteen  or  twenty-five  years  makes 
them  enormously  productive.  Individual  trees  in  old  and  well-kept 
groves  have  been  known  to  produce  forty  boxes  of  oranges  in  one  season. 
Seedling  trees  that  are  planted  twenty  feet  apart,  and  well  cared-for, 
will  become  crowded  when  they  are  twenty  or  twenty-five  years  old. 
The  side  branches  then  make  a  feeble  growth,  the  trees  become  tall,  and 
produce  fruit  chiefly  on  the  upper  part.  Under  such  circumstances  the 
expense  of  gathering  is  increased  and  there  is  a  greater  proportion  of 
poor  fruit.  The  trees  should  be  pruned  so  as  to  admit  more  light  to 
the  lower  branches,  which  is  sometimes  done  by  shortening-in  the  side 
limbs  and  heading-back.  But  a  better  way  is  to  bud-over,  and  remove 
the  tops  of  every  other  tree,  so  that  the  new  tops  will  alternate  with  the 
tall  seedling  trees  both  ways  in  every  row.  Seedlings  sixteen  years  old, 
when  budded  have  each  produced  eight  boxes  of  fine  Washington  Navels 
during  the  next  four  years,  while  the  alternating  seedling  trees,  not 
budded,  produced  more  fruit  per  tree  and  of  much  better  quality  than 
they  did  before  the  others  were  budded.  The  accompanying  photograph 
(plate  1)  shows  the  splendid  growth  of  a  four-year-old  Navel  orange  top 
on  a  sixteen-year-old  seedling.  The  tree  was  beheaded  six  weeks  after 
budding,  and  was  protected  from  frost  by  palm  leaves. 

Blood  Oranges. — Ruby  is  the  earliest  of  the  desirable  varieties  of 
blood  oranges,  and  is  a  prolific  bearer.     The  fruit  is  rather  small  at  the 


—  9  — 

Pomona  substation,  but  it  has  a  high  color  and  fine  flavor.  Malta 
Blood  is  larger  than  the  Ruby,  but  it  bears  less  and  is  a  poorer  orange. 
There  is  only  a  light  demand  for  either  variety. 

Mediterranean  Sweet. — This  kind  was  at  one  time  popular,  but  its 
tendency  to  bear  small  crops  in  certain  sections,  even  under  the  best  of 
care,  makes  it  untrustworthy.  Numbers  of  Mediterraneans  are  being 
budded-over  to  Washington  Navels. 


PLATE  1.    Old  Seedling  Orange  Budded  to  Washington  Navel. 
Four-year-old  top  on  sixteen-year-old  seedling. 

SL  Michael  Paper-Rind. — This  is  an  old  variety,  which,  though 
strongly  approved  by  some  growers,  is  not  now  being  planted  to  any 
appreciable  extent  for  commercial  purposes.  It  is  a  small,  late  variety, 
with  extremely  thin  rind,  and,  as  it  is  of  high  quality,  can  be  recom- 
mended for  family  orchards. 

Miscellaneous  Varieties. — Many  varieties  of  oranges  that  have  no 
recognized  commercial  standing  have  long  been  classed  as  " seedlings  " 


—  10  — 

by  the  trade,  and  therefore  are  of  lessening  importance  in  citrus-fruit 
districts.  Nevertheless,  new  varieties  from  all  parts  of  the  world  are 
worth  testing,  together  with  promising  sorts  of  local  origin,  and  while 
very  few  of  them  can  expect  to  gain  a  place  in  commerce,  many  will  be 
useful  in  gardens.  The  required  standards,  as  shown  by  citrus  fairs, 
are  each  year  more  rigorous.  These  standards  are  given  at  the  end  of 
this  bulletin. 

THE  STOCK  FOR  CITRUS  FRUITS. 

Little   attention   has   been   given   in   California  to  the  hardiness  of 
different  budding-stocks.     At   a   time  when    some   sour-orange    stocks 


PLATE  2.    Root-Systems  of  Seedlings. 

a.  Florida  Sour-Seedling,    b.  Pomelo  Seedling,    c.  Common  Sweet-Seedling. 
All  of  the  same  age— 18  months. 


were  imported  from  Florida,  a  few  trees  budded  on  this  root  were 
planted;  but  the  demand  for  citrus  fruit  trees  rapidly  increased,  and 
horticultural  quarantine  laws  came  into  operation  against  importation, 
so  that  the  use  of  stocks  grown  from  native  sweet-seedlings  became 
general.  This  is  still  considered  "as  good  as  any"  by  nearly  all  of  our 
orchardists.  Some  use  pomelo  (Citrus  aurantium  var.  Pomelanus, 
Willd.),  and  a  few  use  the  native  wild  orange  of  Florida  (0.  vulgaris 
var.  Bigaradia,  Risso). 


—  11  — 

The  root-systems  of  these  three  stocks  vary  considerably,  even  in  the 
seedling-beds.  At  the  age  of  eighteen  months  from  the  seed  there  is 
little  difference  between  the  root-systems  of  the  Florida  sour  and  the 
pomelo  (plate  2,  a  and  b),  though  the  former  is  better  balanced.  The 
sweet-orange  seedling  (plate  2,  c)  is  but  moderately  well  supplied  with 
fibrous  roots,  which  soon  develop  at  the  expense  of  the  crooked  and 
irregular  tap-root. 

Sweet-Stock  Root-System.—  In  a  porous  soil  which  has  been  well  watered 
from  the  time  of  planting,  the  main  mass  of  the  root-system  of  bearing 
trees  on  sweet-orange  stock  concentrates  in  a  horizontal  layer  about 
eighteen  inches  thick,  the  top  of  which  is  eight  or  ten  inches  from  the 
surface.     This  is  well  illustrated  by  the  accompanying  view  of  the  main 


PLATE  3.    Main  Root-System  of  a  Thirty-Year-Old  Sweet-Seedling. 

roots  of  a  tree  that  had  grown  in  a  rich,  sandy  loam  for  thirty  years 
where  artesian  water  was  cheap  and  abundant  and  was  freely  used 
during  the  entire  life  of  the  tree.  (See  plate  3.)  Two  hundred  trees 
that  were  pulled  from  the  ground  in  the  same  orchard  showed  the  same 
kind  of  a  root-system.  Over- irrigation  might  be  thought  responsible 
for  this  shallow  rooting,  but  ten  acres  of  the  same  variety  that  grew  for 
sixteen  years  in  a  soil  containing  more  sand  and  gravel  than  that  just 
described,  where  water  was  always  scarce  and  expensive,  had  the  root- 
systems  distributed  in  much  the  same  way.  (See  plate  4.)  In  the 
heavy  soil  of  Riverside  the  same  condition  prevails.  In  short,  the 
general  experience  on  all  kinds  of  soils  and  under  different  methods  of 
irrigation  shows  that  it  is  the  nature  of  the  sweet-orange  seedling  to  form 
a  shallow  root-system. 


—  12  — 

Careful  studies  of  the  root-systems  of  sweet-oranges  have  been  made 
at  the  Pomona  substation,  where  the  trees  have  always  received  deep 
and  thorough  irrigation,  the  water  having  been  allowed  to  run  from 
forty-eight  to  seventy-two  hours  at  a  time.  Deep  irrigation  was  here 
followed  by  deep  cultivation  from  the  time  the  trees  were  planted,  and 
this  somewhat  discouraged  but  did  not  remove  the  shallow-rooting 
tendency.  The  ten-year-old  Washington  Navel  on  sweet-seedling  stock, 
illustrated  in  plate  5,  fig.  1,  had  three  of  its  heaviest  lateral  roots, 
starting  out  six  inches  below  the  surface,  severed  by  the  plow,  at  a  dis- 
tance of  two  feet  from  the  tree  and  of  ten  inches  below  the  surface. 
(a  in  plate  5.)  At  this  point  a  secondary  lateral  (6)  developed,  and 
descended  at  an  angle  of  about  sixty  degrees  from  the  perpendicular, 
until  it  reached  a  depth  of  two  feet,  when  it  assumed   an  almost  hori- 


PLATE  4.    Root  and  Stem  of  Sixteen-Year-Old  Orange  Tree  on  Light 
Sandy  Soil.    Has  always  been  short  of  water. 

zontal  position.  As  no  fertilizers  have  ever  been  applied  to  the  orchard 
there  could  have  been  no  influence  from  that  source  which  would  cause 
the  roots  to  come  near  the  surface.  The  original  tap-root  had  not  pene- 
trated deeper  than  four  feet  ten  inches  (c  in  plate  5).  The  longest 
lateral  had  a  total  length  of  fourteen  feet,  with  many  turns,  at  no  time 
going  deeper  than  one  foot.  From  the  main  laterals  were  numerous 
secondary  laterals  that  penetrated  from  one  to  two  feet,  and  from  these 
numerous  fibrous  roots  extended  through  the  soil  in  all  directions.  To 
sum  this  up,  the  sweet-orange  is  a  surface-growing  stock  which  has  few  or 
no  deeply-penetrating  roots. 


Advantages  of  Pomelo  Stock. — Nearly  all  the  orange  trees  now  bearing 
in  Southern  California  are  budded  on  sweet-orange  stock,  but  the 
pomelo  is   rapidly   taking   its   place.     There   is    still   some   prejudice 


—  13  — 

against  this  as  a  budding  stock,  as  some  growers  think  it  less  hardy 
than  the  sweet-orange.  It  makes,  however,  a  very  healthy  tree,  and  is 
said  to  stand  next  in  value  to  the  sour,  or  hardy,  stock  among  Florida 
growers.  The  seed  of  the  pomelo  is  easily  obtained,  and  it  germinates 
more  quickly  than  does  orange  seed.  The  root-system  of  a  one-year-old 
pomelo  seedling  is  excellent,  but  the  tap-root  is  crooked,  like  that  of  the 
sweet-orange.      (See  plate  5,  fig.  2.)     Some  of  the  lateral  roots  of  the 


Fig.  1.  Fig.  2. 

PLATE  5.    Root-Systems  of  Sweet-Orange  and  Pomelo  Stocks, 

Fig.  1.    Sweet-orange  stock;  ten  years  from  time  of  planting. 
Fig.  2.    Pomelo  stock;  seven  years  old. 

pomelo  soon  develop  at  the  expense  of  the  tap-root,  making  a  prodigious 
growth.  A  seven-year-old  seedling  pomelo,  whose  root-system  was 
studied  at  the  substation,  had  a  tap-root  four  feet  long,  making  a 
healthy  though  small  growth,  while  the  largest  lateral  root  started  two 
feet  below  the  surface  and  extended  for  a  distance  of  twenty-six  feet, 
or  two  feet  beyond  where  the  next  tree  was  planted,  at  an  average 
depth  of  about  eighteen  inches  below  the  surface.     Over  ninety  per  cent 


—  14  — 


—  15  — 

of  the  root-system  exposed  was  found  to  be  confined  to  a  layer  between 
ten  inches  and  two  feet  below  the  surface.  The  accompanying  views  on 
plate  5  show  the  superiority  of  the  pomelo  over  the  sweet-orange  in 
mere  root  development.  The  seven-year-old  pomelo,  figure  2,  had  pro- 
portionately a  much  larger  number  of  fibrous  roots  than  the  ten-year- 
old  sweet-seedling.  The  pomelo  roots  ran  deeper  beneath  the  surface 
than  the  sweet-orange,  the  majority  sinking  below  fifteen  inches. 
Plates  6  and  8  show  drawings  of  the  root-systems  of  sweet-orange,  of 
pomelo,  and  of  Florida  sour  stocks,  which  further  illustrate  these  points. 

The  Florida  Sour-Orange. — The  sour-orange  stock  was  introduced 
into  Southern  California  by  Twogood  &  Cutter,  of  Riverside,  during  the 
early  days  of  citrus  planting.  It  is  a  very  useful  budding  stock,  is 
called  one  of  the  most  hardy  of  the  strong-growing  citrus  fruits,  and  is 
used  extensively  in  Florida  and  Europe  in  localities  where  the  "foot 
rot"  or  "mal  di  goma"  is  liable  to  attack  orange  trees. 

There  has  been  much  discussion  among  orange-growers  in  California 
as  to  the  relative  merits  of  sweet-  and  sour-orange  stocks,  and  even  now 
there  seems  to  be  no  generally  recognized  superiority  of  either.  Grow- 
ers having  orchards  on  sweet-stock  claim  that  it  is  as  good  as  any, 
while  those  having  trees  budded  on  sour-stock  think  the  same  of  them. 
Disinterested  judges  have  said  that  they  can  see  no  difference  where  the 
two  stocks  have  received  the  best  of  care.  One  of  the  thriftiest  Wash- 
ington Navel  groves  in  the  Riverside  section  is  budded  on  sour-stock, 
but  during  its  early  bearing  period  this  sour-stock  grove  did  not  pro- 
duce as  much  fruit  as  did  other  groves  of  the  same  age  which  were 
budded  on  sweet  seedlings.  In  recent  years,  however,  it  has  been  pro- 
ducing abundant  crops.  On  the  grounds  of  the  substation  Washington 
Navel  trees  budded  on  both  varieties  of  stock  have  always  had  the  same 
care,  and  on  an  average  have  produced  equally  well,  when  the  same 
stock  developed  numerous  laterals.  The  deep  rooting  of  a  Florida  sour- 
stock  at  the  substation  is  well  illustrated  by  plate  7,  which  shows  a 
nine-year-old  Washington  Navel  tree  and  its  sour-stock  root-system. 
The  longest  and  uppermost  lateral  started  six  inches  below  the  surface 
and  descended  at  once  at  an  angle  of  forty-five  degrees  until  two  feet 
below  the  surface;  then  extended  in  a  horizontal  position  for  ten  feet 
from  the  tree  and  rose  to  within  eight  inches  of  the  surface,  when  it  was 
cut  by  the  plow.  It  then  grew  downward  to  one  foot  and  horizontal 
for  eight  feet  more.     The  longest  tap-root  was  nine  and  one  half  feet. 

Individual  sour-stock  roots  differ  from  each  other  in  manner  of 
growth.  A  number  of  trees  were  examined  and  the  numerous  tap-roots 
went  deep  in  every  case.  Those  trees  which  had  few  lateral  roots  made 
less  growth  and  produced  a  much  smaller  amount  of  fruit  than  those 
which  had  numerous  laterals  near  the  surface.     The  root-systems  of 


16 


PLATE  7.    Washington  Navel  on  Florida  Sour-Stock  Root.    Nine  Years  Old. 


—  17  — 


2— Bul.  138 


—  18  — 

two  of  these  Florida  sour-stocks  at  the  substation  are  shown  by  draw- 
ings on  plate  8.  It  is  plainly  a  very  strong,  healthy,  and  valuable  root- 
system.  The  orange  tree  shown  on  the  left  side  of  the  chart  bore  110 
pounds  of  oranges  when  nine  years  old.  The  descending  roots  were 
traced  to  nine  feet  from  the  surface.  The  other  tree,  shown  in  part  at 
the  right  side  of  the  chart,  bore  204  pounds  of  oranges  when  eight  years 
old.  The  accompanying  data  shown  in  the  illustration  are  well  worth 
studying. 

There  has  been  some  complaint  among  growers  that  Navel  orange 
trees  budded  on  sour-stock  become  more  liable  to  frost  than  those  budded 
on  sweet-seedlings.  This  is  not  confirmed  by  recorded  observations. 
A  letter  from  Grao,  Spain,  in  the  United  States  Consular  Reports,  says 
that  stocks  from  the  sour-orange  raised  from  seed  "are  more  vigorous, 
more  luxuriant,  and  of  longer  duration;  besides,  they  best  resist  the 
cold,  for  which  reason  they  are  preferred  and  chosen  for  the  trunks  of 
trees  of  tall  growth."  At  the  Pomona  substation  there  has  not  been 
any  noticeable  difference  in  the  hardiness  of  orange  trees  grown  on  the 
two  kinds  of  stock  — sweet-orange  and  Florida  sour. 

It  has  been  claimed  by  some  growers  that  sour-stock  has  an  influence 
on  the  quality  of  the  orange.  Several  firms  who  handle  large  quantities 
of  all  kinds  of  fruit  from  both  California  and  Florida  were  asked  if  they 
had  discovered  any  such  difference.  P.  Ruhlman  &  Co.,  of  New  York, 
wrote  under  date  of  July  1,  1901:  "  We  are  not  able  to  enlighten  you  as 
regards  the  difference  in  the  eating-  and  keeping-qualities  of  oranges 
grown  on  sweet-  and  sour-stock.  In  our  judgment  the  soil  has  every- 
thing to  do  with  the  keeping-quality  of  oranges.  For  instance,  we  have 
known  several  orchards  whose  fruit  formerly  arrived  from  Florida  in 
decaying  condition,  whether  it  was  shipped  early  or  late.  Now,  by 
proper  fertilizing,  and  principally  the  use  of  potash,*  the  fruit  has 
changed  in  character  and  become  of  the  best  keeping-quality  (would 
hold  up  for  a  month)." 

James  S.  Watson,  president  of  Porter  Bros.  &  Co.,  of  Chicago,  wrote, 
July  8, 1901 :  "  We  consider  oranges  budded  on  sour-stock  to  be  of  better 
eating-quality  and  to  have  better  keeping-qualities  than  those  budded 
on  sweet-stock.     That  has  been  our  experience,  especially  in  Florida." 

The  chemical  analyses  of  oranges  grown  on  sweet-stock  and  on  sour- 
stock,  made  at  Berkeley  by  the  California  Experiment  Station,  and 
published  in  previous  reports,  show  such  slight  variations,  easily  aris- 
ing from  unavoidable  differences  in  the  ripeness  of  the  specimens  used, 
that  the  theory  of  the  poorer  quality  of  fruit  grown  on  sour-stock  can 
not  be  justified. 


*The  soils  of  Florida,  as  shown  by  many  analyses,  are  very  deficient  in  potash. 


19  — 

Conclusions  Respecting  Stocks. — The  reader,  examining  with  care  the 
quite  different  root-systems  shown  in  the  preceding  illustrations,  and 
following  the  observations  heretofore  given  in  this  paper,  will  be  pre- 
pared to  form  a  trustworthy  opinion  of  his  own.  He  will  note  that  the 
sweet-orange  root  is  a  persistent  surface-feeder,  having  almost  its  entire 
root-s}^stem  above  a  depth  of  eighteen  inches  and  rising  to  within  eight 
inches  of  the  surface.  This  stock,  he  will  observe,  produces  an  abun- 
dance of  fibrous  roots  that  concentrate  near  the  surface,  just  beneath 
the  reach  of  the  plow  and  cultivator,  thus  making  the  tree  too  suscep- 
tible to  drought. 

On  the  other  hand,  the  root  of  the  sour-orange  penetrates  to  a  depth 
of  nine  feet  or  more  (see  plates  7  and  8),  sometimes  having  numerous 
laterals  near  the  surface,  and  sometimes  having  fewer  but  more  sharply 
descending  laterals.  Both  a  deep  root-system  and  broadly  extending 
laterals,  not  too  near  the  surface,  are  essential  to  the  ideal  stock.  There 
would  seem  to  be  room  for  some  selection  among  sour-stocks  so  as  to 
obtain  these  qualities  in  the  highest  possible  degree.  Though  the  sour- 
stock  does  not  appear  to  bring  trees  into  full  bearing  as  soon  as  do  the 
sweet-orange  and  the  pomelo  stocks,  the  value  of  the  sour-stock  in  other 
directions  may  compensate  for  this  defect,  and  it  seems  probable  that  in 
localities  where  the  sweet-stock  fails,  sour-stock  will  be  used  to  a  greater 
extent  than  now. 

It  has  been  shown  that  the  pomelo  laterals  are  found  at  a  somewhat 
greater  depth  than  the  laterals  of  the  sweet-orange.  The  pomelo  pro- 
duces more  fibrous  roots  than  do  either  of  the  other  stocks,  and  con- 
sequently the  tree  is  a  ravenous  feeder.  It  is  resistant,  to  a  certain 
extent,  to  the  form  of  gum  disease  that  attacks  the  roots  of  citrus  trees. 
On  the  whole,  the  pomelo  is  deservedly  becoming  the  favorite  stock  in 
Southern  California.  In  practice  it  has  succeeded  better  at  the  station 
than  has  the  sour-stock,  which  seems  to  lack  uniformity  of  root  growth, 
sometimes  having  few  laterals,  in  which  case  the  crops  are  small.  The 
pomelo  seedlings  have  made  the  best  growth  in  the  nursery. 

METHODS  OF  PLANTING  ORCHARDS. 

The  land  chosen  for  the  site  of  an  orange  grove  should  be  surveyed, 
and  well  graded  wherever  necessary,  so  that  water  will  flow  to  every 
part  of  the  tract  from  the  main  pipes  or  ditches.  It  ought  to  be  thor- 
oughly worked,  at  least  a  foot  deep,  plowing  twice  and  harrowing  well; 
a  subsoiler  attachment  can  be  used  to  loosen  the  soil  several  inches 
below  the  bottom  of  the  plow-furrows.  The  orange  tree  requires  a 
warm,  rich,  and  well-drained  soil,  which  receives  the  best  of  cultivation. 
The  water  system  must  be  under  complete  control,  so  that  waste  and 
over-irrigation  can  be  avoided.     The  soils  of  the  orange  sections  vary 


—  20  — 

considerably  in  respect  to  the  percentage  of  sand,  decomposed  granite, 
limestone,  or  red  oxid  of  iron  which  is  claimed  to  give  high  color  to  the 
fruit,  but  all  are  suited  to  irrigation  and  have  a  porous,  well-drained 
subsoil. 

The  Ordinary  Transplanting  Method. — The  almost  universal  method 
of  moving  young  orange  trees  from  the  nursery  is  to  cut  off  a  large  part 
of  the  top,  leaving  short  stubs  of  branches,  and  even  from  these  the 
leaves  are  sometimes  stripped.  This,  of  course,  is  to  balance  the  loss  of 
a  large  part  of  the  root-system  at  the  time  of  transplanting,  and  to 
lessen  evaporation.  Twenty  or  thirty  gallons  of  water  are  usually 
given  to  each  tree  at  the  time  of  planting.  If  the  leaves  do  not  fall 
after  the  trees  have  been  planted  a  short  time,  but  show  a  disposition  to 
turn  yellow,  they  should  be  removed. 

The  Reed  System  of  Transplanting. — Much  better  results  are  obtained 
by  the  method  adopted  by  Mr.  J.  H.  Reed,  of  Riverside.  According  to 
his  method,  vigorous  trees  are  selected  in  the  nursery,  and  are  well 
watered  before  removal.  The  longer  branches  are  but  slightly  cut  back, 
leaving  most  of  the  foliage  on.  The  trees  are  then  lifted  with  large 
balls  of  earth,  and  are  taken  directly  to  the  plantation,  where  holes  two 
feet  deep  and  two  and  a  half  feet  wide  have  been  prepared,  into  which 
they  are  placed,  and  the  earth  is  well  filled-in  around  each  ball,  not 
firmed,  but  settled  with  water,  so  that  the  trees  will  stand  at  the  same 
height  as  they  did  at  the  nursery.  No  planting  should  be  done  unless 
there  is  irrigation  water  available  at  the  time.  After  the  ground  has 
been  soaked  for  several  feet  on  all  sides  of  the  newly-set  trees,  thorough 
cultivation  should  follow,  as  soon  as  the  land  is  in  a  proper  condition. 
Under  any  system  of  transplanting  this  is  good  practice. 

Mr.  Reed  says  further :  "A  small  amount  of  fertilizer  is  applied  soon 
after  planting,  for  the  young  roots  to  use  when  they  first  start  out  from 
the  balls.  A  pure  bat  guano  with  a  high  percentage  of  nitrogen,  about 
three  fourths  of  a  pound  to  the  tree,  has  been  found  to  give  the  best 
results ;  but  any  commercial  fertilizer  rich  in  nitrogen,  or  animal  fer- 
tilizer, if  placed  properly  and  kept  moist,  answers  well.  It  is  applied 
in  trenches  each  side  of  the  ball,  at  right  angles  with  the  irrigation 
furrows,  and  reaching  to  them.  They  may  be  made  by  plowing  a  deep 
furrow  and  deepening  with  a  shovel  to  ten  or  twelve  inches.  The 
material  is  carefully  distributed  and  slightly  mixed  with  the  earth  at 
the  bottom  of  the  furrows ;  the  water  from  the  irrigating  furrows  keep- 
ing this  always  moist,  it  is  available  as  soon  as  reached  by  the  rootlets. 
This  also  tends  to  deep  rooting.  Thorough  irrigation  should  follow 
planting  every  twelve  or  fifteen  days  during  the  first  summer.  The 
whole  space  between  the  rows  should  be  thoroughly  and  deeply  wet — 


21  — 


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22  - 

not  merely  a  narrow  strip  on  each  side  of  the  rows.  I  have  traced  roots 
that  have  grown  during  the  first  summer  over  six  feet  from  the  tree, 
and  these  should  be  well  supplied  with  moisture  at  all  times." 


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The  advantage  claimed  for  the  Reed  method  is  that  it  retains  the  top 
of  the  tree,  and  makes  use  of  it  immediately.  This  retention  of  nearly 
all  the  leaves  and  branches  enables  trees  under  proper  conditions  to 


—  23  — 

produce  a  much  more  vigorous  growth  than  under  the  ordinary  system 
of  severe  pruning,  when  moved  from  the  nursery.  The  best  of  care  is 
essential  to  success  in  this  method.  If  trees  are  to  receive  poor  or  only 
ordinary  treatment  after  being  set  in  the  orchard,  the  common  method 
of  severe  pruning  is  best.  Mr.  Reed  himself  prunes  back  any  trees  that 
show  lack  of  vigor  after  being  transplanted,  watered,  and  fertilized. 

The  good  start  given  to  trees  by  the  Reed  method  is  shown  in  their 
size,  vigor,  and  productiveness  for  an  indefinite  time,  and  it  is  also 
claimed  that  a  crop  of  oranges  is  obtained,  without  injury  to  the  trees, 
one  year  earlier  than  if  they  were  planted  by  the  usual  method.  Trees 
thus  planted  (on  the  Reed  system)  produced  over  one  hundred  boxes  of 
oranges  on  ten  acres,  the  second  year  from  planting,  and  one  box  per 
tree  three  years  from  the  time  of  planting.  The  trees  are  shown  in 
plate  9.  Ten  acres  of  trees  five  years  old  produced  2,500  boxes.  There 
was  no  appreciable  injury  done  the  young  trees  on  account  of  the  early 
bearing,  for  they  continued  to  make  a  sturdy  growth  while  maturing 
the  crop  of  fruit.  Trees  planted  in  the  usual  way  one  year  before,  on 
adjoining  land  that  is  similar  in  character,  although  receiving  good  care 
from  the  start,  are  not  now  as  large  as  those  of  Mr.  Reed,  though  appar- 
ently thrifty. 

This  method  of  transferring  trees  to  the  orchard  and  securing  their 
rapid  establishment  there,  is  based  upon  intelligent  selection  in  the 
nursery  and  very  careful  attention  to  details  after  transplanting. 
Mr.  Reed  does  not  claim  that  he  originated  the  method,  but  it  has  not 
been  observed  except  in  his  orchard,  which  furnishes  an  excellent  illus- 
tration of  its  value  under  proper  conditions.  The  photographs  given  on 
plate  10  show  the  contrasts  between  an  orchard  planted  by  ordinary 
cutting-back  methods  and  one  planted  on  the  Reed  system. 

The  "Post-holev  Method. — There  is  another  new  system  of  planting 
orange  trees  that  is  being  used  at  the  Southern  California  substation, 
but  practical  work  has  not  been  carried  on  long  enough  to  demonstrate 
its  real  value.  In  this  method,  holes  are  bored  with  a  post-hole  auger 
in  the  bottoms  of  the  regular-sized  tree-holes,  to  a  depth  of  five  or  six 
feet.  They  are  filled  up  to  the  point  at  which  the  bottom  of  the  tree 
rests  with  peat  or  well-prepared  compost,  thus  affording  good  drainage. 
The  roots,  it  is  thought,  will  follow  this  rich  soil  downward,  and  thus 
establish  a  deeper  root-system.  In  selecting  a  soil  for  any  "post-hole" 
planting,  it  is  very  important  to  remember  that  young  orange  roots  are 
easily  injured  by  alkali  or  strong  fertilizers,  and  care  should  be  taken 
to  avoid  an  injurious  compost  or  one  that  prevents  free  drainage. 


24 


WORKING-OVER  OLD  ORCHARDS. 

In  every  fruit  district,  the  introduction  of  inferior  varieties  necessarily 
causes  much  loss  to  growers,  as  it  is  expensive  to  replant  or  to  work- 
over  old  orchards.  This  is  the  price  that  horticulturists  willingly  pay 
for  new  and  improved  varieties.  The  orange-growers  of  Southern  Cali- 
fornia have  experimented  with  almost  every  known  variety,  and  have 
been  compelled  to  abandon  a  number  that  once  were  popular.  The 
heaviest  loss  incurred  was  because  of  the  inferior  Australian  Navel 
which  preceded  the  Washington  Navel  and  sufficiently  resembles  it  in 
growth  to  have  been  sold  in  numbers  of  cases  for  that  far  better  variety. 


PLATE  11.  Working-Over  Old  Orchards.  Old  Mediterranean  Sweet 
re-budded  to  Washington  Navel.  Tops  left  on  during  first  winter  as 
protection  against  frost. 

In  recent  years  many  trees  of  Australian  Navel,  Mediterranean  Sweet, 
and  seedlings  have  been  re-budded  to  the  Washington  Navel  and  its 
improved  types. 

While  it  is  easy  to  perform  the  operation  of  budding,  it  requires 
special  knowledge  and  skill  to  get  the  new  tree-top  rightly  started  and 
through  the  first  season.  Even  an  old  orange  tree  will  take  buds  in  the 
main  branches  or  trunk,  and  will  produce  a  luxuriant  growth  from  the 
buds  the  first  year,  if  properly  managed.  But  if  such  trees  lose  their 
tops  after  the  first  summer's  growth,  they  are  usually  worthless,  or  are 
not  profitable  for  years.  In  such  cases  it  is  better  to  take  out  the  trees 
and  plant  young  budded  trees  from  the  nursery. 

The  Method  of  Re-budding  Trees. — Old  Mediterranean  Sweets  are 
among  the  most  difficult  of  citrus  trees  to  re-bud,  and  very  poor  results 


—  25  — 


will  be  obtained  if  they  are  handled  by  ordinary  methods.  Mr.  E.  L. 
Koethen  and  Mr.  O.  D.  Wilheit,  of  Riverside,  have  been  very  successful 
in  budding-over  all  kinds  of  old  citrus  trees,  including  Mediterranean 
Sweets.  They  trim  out  all  branches  that  are  not  used  to  insert  buds 
into,  and  then  thin  out  the  remaining  branches  above  where  the  buds 
are  inserted.  This  is  done  early  in  the  spring,  and  at  the  time  of  bud- 
ding. The  removal  of 
surplus  limbs  directs 
the  entire  flow  of  sap 
into  the  branches  con- 
taining the  buds,  which 
results  in  their  healing- 
over  quickly  and  be- 
coming well  united. 
Upon  the  removal  of 
the  tops  of  the  trees, 
the  buds  start  at  once. 
All  saw  cuts  are  covered 
with  some  material  that 
will  exclude  the  air, 
usually  grafting  wax, 
though  Mr.  Koethen 
has  experimented  with 
thin  putty,  and  finds 
it  much  cheaper,  more 
durable,  and  not  inju- 
rious to  the  tree.  After 
the  tops  are  removed, 
the  trees  should  be 
whitewashed  to  prevent 
sunburn. 


mmmMP 


PLATE  12. 


Working-Over  Old  Orchards. 
Placing  the  bud. 


Value  of  il  Cured"  Buds. — The  best  success  comes  from  using  "cured" 
buds;  these  are  buds  that  have  been  cut  from  the  tree  and  kept  in  damp 
sand  or  moss  for  a  few  weeks  before  using.  When  treated  in  this  way 
they  become  tougher,  and  when  inserted  into  a  tree  that  has  freely- 
flowing  sap  they  absorb  it  more  readily.  When  buds  are  well  cured, 
and  not  allowed  to  become  either  too  wet  or  too  dry,  they  are  not  easily 
injured  in  handling.  The  delicate  germ  is  very  brittle  when  the  scion 
is  first  cut  from  the  tree,  and  the  slightest  touch  will  sometimes  destroy  it. 

Placing  the  Bud. — The  incision  which  is  to  receive  the  bud  is  made  by 
running  the  knife  down  the  side  of  the  branch  or  trunk  of  the  tree. 
The  cross-cut  is  made  at  the  lower  end  of  the  incision  instead  of  at  the 
top,  as  is  the  usual  method,  and  slants  upward.     By  giving  the  knife  a 


—  26  — 

slight  twist  before  removing  it  from  the  last  cut,  the  two  corners  are 
turned  out,  which,  with  the  upward  slant,  forms  an  opening,  into  which 
the  bud  slips  easily.  Narrow  strips  of  waxed  cloth  are  then  wrapped 
around  the  limb,  completely  covering  the  inserted  bud  and  the  incisions- 
The  insertion  of  the  buds  from  below  gives  better  protection  from  rain 
and  dew.     (See  plate  12.) 

When  to  Remove  the  Bands. — These  waxed  bands  are  allowed  to 
remain  on  the  buds  for  from  four  to  six  weeks,  according  to  the  weather. 
During  such  a  season  as  the  spring  of  1901,  which  was  cool  and  damp, 
citrus  trees  make  very  little  growth.  Under  these  circumstances  the 
waxed  bands  should  remain  a  longer  time.     The  bands  were  removed 


PLATE  13.  Working-Over  Old  Orchards.  Sixteen-year-old  seedling, 
budded  and  topped.  1.  Before  beheading.  2.  After  beheading. 
3.  New  growth  three  months  after  beheading. 

from  the  buds  after  four  weeks  (the  usual  period)  in  a  number  of  cases 
in  the  Pomona  Valley  in  1901,  and  they  generally  died,  but  in  the  same 
year  when  the  bands  were  allowed  to  remain  on  the  buds  for  six  weeks 
the  result  was  satisfactory. 

Removal  of  the  Tops. — There  are  three  usual  methods  of  removing  the 
tops  after  budding:  (1)  the  removal  of  the  entire  top  at  the  time  of 
taking  the  bands  from  the  buds;  (2)  the  removal  of  all  branches  but 
one,  which  is  left  to  draw  sap;  and  (3)  the  girdling  of  the  limbs  above 
the  buds  while  still  retaining  the  entire  top  for  one  year. 

When  the  first  method  (illustrated  in  plate  13,  and  also  in  plate  14) 


—  27 


e 

bo 


^4 

o3 


P. 
O 


n 
o 

-o 

M 
03 

,C 

CJ 

S-l 

o 

o 
<u 

c 

03 
t-i 
03 
0> 

a 
p. 
< 


w 
Q 
A 
< 
X 
o 
M 

o 


C5 

Pi 
o 


H 


—  28  — 

is  practiced  and  proper  protection  is  given  to  the  buds  and  young  top 
during  the  first  year,  better  results  seem  to  be  obtained  than  by  any 
other  way.  The  new  top  receives  the  entire  nourishment  afforded  by 
the  tree;  with  frequent  pinching-back  of  the  new  branches,  the  wood 
can  be  hardened  and  better  matured  before  winter,  and  the  leaves 
become  thick  and  heavy,  affording  much  frost-protection.  This  is 
shown  in  plate  15.  Both  trees  were  budded  in  May;  No.  1  was  topped 
in  June  at  the  time  of  removing  the  bands;  No.  2  was  topped  in  July, 
one  month  after  bands  were  removed.  The  photographs  were  taken  a 
year  later,  and  are  typical  of  five-acre  blocks.     But  when  this  method  is 


1  2 

PLATE  15.  Wokking-Over  Old  Orchards.  1.  Topped  when  bands 
were  removed.  2.  Topped  one  month  after  bands  were  removed. 
Photographs  taken  one  year  later. 

employed  in  frosty  sections,  the  tops  must  be  protected  still  further 
during  the  first  winter.  The  young  growth  will  be  killed  when  the 
thermometer  registers  from  25°  to  27°  Fahr.,  and  if  the  tops  are  killed 
back  to  the  old  wood,  the  trees  will  seldom  or  never  become  useful, 
often  failing  even  to  send  out  suckers.  An  illustration  of  this  frost 
effect  is  shown  in  plate  16. 

The  value  of  protection  to  the  young  top  during  the  first  winter  was 
shown  by  a  lemon  orchard,  in  a  frosty  location,  that  was  budded-over 
to  Washington  Navel  oranges.  When  the  tops  were  removed,  the 
growth  from  the  buds  was  wrapped  with  palm  leaves  during  the  first 
winter;  eighteen  months  after  the  trees  were  budded,  they  were  past  all 
danger  from  frost,  and  were  large  enough  to  produce  a  box  of  oranges 
per  tree.     (See  plate  17.) 


—  29 


PLATE  16.    Working-Over  Old  Orchards. 
unprotected  young  growth. 


Frost  effect  on 


PLATE  17.  Working-Over  Old  Orchards.  Lemon  stock  18  months  after 
being  budded  to  orange;  in  a  frosty  location,  but  protected  by  wrapping 
with  palm  leaves. 


—  80  — 

Seedling  orange  trees  that  were  budded-over  when  sixteen  years  old, 
and  were  protected  by  nailing  palm  leaves  to  the  trunks  and  by  wrap- 
ping the  palm  leaves  around  the  new  tops,  produced  an  average  of  eight 
boxes  per  tree  during  the  first  five  years  after  they  were  so  budded. 

The  second  practice  of  leaving  a  side  branch  on  the  tree  to<"  draw  sap''  is 
a  safe  method,  and  will  sometimes  save  a  tree  if  the  buds  fail  to  grow; 
but  when  budding  is  skillfully  done  there  is  no  need  of  leaving  side 
branches.     (See  plate  18.) 


■: . 


PLATE  IS.    Working-Over  Old  Orchards.    Pomelo  budded  to  orange;  leaving  side  branch  to 

keep  up  circulation. 

Girdling  the  branches  above  the  buds  after  they  have  healed  over  and 
the  bands  have  been  removed,  while  leaving  the  tops  on  until  after  the 
first  winter,  is  not  practiced  widely,  but  has  some  ardent  advocates. 
The  top  when  thus  left  continues  to  draw  enough  sap  to  keep  alive, 
and  to  ripen  a  crop  of  early  and  poor  fruit.  The  removal  of  such  a  top 
after  the  buds  have  made  one  year's  growth  is  sometimes  difficult  with- 
out injuring  the  new  head.  The  chief  advantage  for  this  method  is  that 
the  old  top  forms  a  covering  for  the  new  head,  obviating  the  necessity  of 
wrapping  it  for  protection  against  frost.  Trees  handled  in  this  way  (see 
plate  19)  have  made  a  better  record  than  adjoining  trees  that  had  the 
tops  cut  off  at  the  time  when  the  bands  were  removed  from  the  buds  and 
were  left  unprotected  during  the  first  winter.     (See  plate  20.) 

When  the  leaves  of  fan  palms  are  used,  the  stems  are  tied  around  the 
trunks  of  the  trees  and  the  broad  leaves  are  fastened  around  the  tops. 
After  spring  frosts  are  over,  the  palm  leaves  are  removed.  Sometimes 
the  palm  stems  are  nailed  to  the  trunks  of  the  orange  trees,  which  is 
more  convenient  than  tying.  Though  not  a  praiseworthy  method,  yet 
this  does  not  seem  to  injure  the  trees. 

The  old-time  method  of  cutting  off  the  entire  top  of  a  tree  so  as  to  bud 
upon  suckers  is  now  considered  a  poor  way,  as  a  year  of  time  is  thereby  lost. 


-  31  — 


PLATE  19.     Working-Over  Old  Orchards.    Top  removed  when  buds 
have  a  year's  growth;  protection  given  thus  against  frost. 


PLATE  20.    Working-Over  Old  Orchards.    Top  removed  at  time  of  budding;  no  protection 

made  against  frost  during  first  month. 


32  - 


PRUNING    AND    SHAPING   TREES. 


The  tendency  of  young  trees  of  Washington  Navel  and  some  other 
varieties  to  assume  a  drooping  habit  when  making  a  vigorous  growth  is 
due  to  the  fact  that  the  soft  shoots  are  unable  to  support  the  weight  of 
the  large,  heavy  leaves.  Mr.  Reed  writes  :  "It  can  not  be  expected  that 
the  soft,  succulent  shoots  will  grow  upright  when  they  are  weighed  down 
with  the  great  fat  leaves  that  vigorous  young  Navel  trees  always  pro- 
duce, but  if  they  are  pinched  back  they  will  soon  begin  to  straighten 
up.  If  this  method  is  followed,  a  Washington  Navel  tree  can  be  made 
symmetrical  and  upright.  I  make  it  a  point  to  visit  every  one  of  my 
young  trees  several  times  during  the  season  and  pinch  back  shoots." 

Even  trees  that  have  been  long  in  bearing  will  be  benefited  by 
pinching  back  every  branch  that  takes  too  vigorous  an  upward  growth. 
This  pinching  process  is  especially  necessary  with  trees  from  one  to  five 
years  old. 

Pruning  Bearing  Trees. — The  advantage  of  an  upright  tree  over  a 
drooping  one  is  considerable  when  it  becomes  loaded  with  fruit.  The 
crop  is  borne  with  less  breakage  of  limbs,  and  not  so  much  fruit  is 
injured  with  the  wind.  After  they  are  in  full  bearing,  there  seems  to 
be  no  pruning  that  will  promote  the  health  of  the  trees  or  improve  the 
crop,  other  than  cutting  out  limbs  that  project  abruptly  from  the  side, 
or  those  that  make  a  sudden  skyward  growth,  and  the  constant 
trimming  out  of  dead  or  stunted  wood  that  is  found  on  the  inside  of 
the  trees. 

If  too  close,  the  branches  of  a  tree  should  be  thinned  out  from  the 
inside  until  the  sunlight  has  had  free  access.  This  does  not  make  any 
noticeable  difference  in  the  appearance  of  the  tree,  but  makes  it  bear 
fruit  on  the  inside.  Such  fruit  is  safe  from  sunburn  and  frost,  and 
packs  as  " fancy"  grade.  By  early  attention  to  pruning,  the  trees  need 
never  be  allowed  to  grow  too  close  in  the  center. 

Renewal  of  Tops. — There  are  some  groves  of  old  orange  trees  that  do 
not  respond  to  the  best  treatment  that  the  owners  can  give  them. 
Under  such  circumstances,  the  most  effective  way  to  stimulate  new  life 
and  vigor  is  sometimes  to  remove  the  entire  top,  leaving  enough  of  each  of 
the  main  limbs  to  distribute  equally  the  suckers  that  will  afterward  make 
the  new  top  of  the  tree.  If  the  tops  are  only  thinned  out  and  but  par- 
tially cut  back,  there  will  be  a  proportionate  amount  of  feeble  growth  and 
a  corresponding  lack  of  productiveness.  An  old  orange  tree  will  rapidly 
produce  a  new  top,  even  when  cut  back  to  a  mere  stump.  It  is  soon 
in  a  condition  to  bear  again  at  its  full  capacity.  When  the  roots  are 
healthy  and  the  soil  is  properly  cultivated  and  fertilized,  the  orange 


—  33  — 

tree  appears  able  to  produce  several  generations  of  tops  on  one  stock. 
But  it  will  generally  be  found  that  the  trouble  with  old,  non-productive 
trees  lies  in  the  root-system,  or  in  the  management  of  soil,  or  in  both. 
Thorough  investigation  of  roots  and  soil  should  be  made  before  any 
severe  cutting  or  pruning  of  the  top  is  resorted  to. 

Except  as  noted  in  preceding  paragraphs,  all  trees  should  be  trained 
low  for  protection  against  frost,  heat,  and  wind,  and  to  aid  the  gathering 
of  fruit.  Heavily-laden  branches  are  generally  propped  to  prevent 
breaking  down,  as  the  loss  from  dropping  and  splitting  is  so  great  that 
the  trees  cannot  be  safely  lightened  by  thinning  of  fruit  when  small. 

CULTIVATION  AND  IRRIGATION. 

During  the  past  seven  years  the  substation  grove  has  been  plowed 
deeply  at  least  twice  north  and  south  one  year,  and  twice  east  and 
west  the  next.  Every  year  the  plow  turns  up  masses  of  fibrous  roots 
that  grow  just  below  the  reach  of  the  cultivator  teeth,  in  the  strip  of 
land  between  the  trees  in  the  rows  running  in  the  direction  of  the  last 
plowing.  These  roots  grow  from  five  to  twelve  inches  below  the  surface 
during  the  winter  and  spring  when  the  soil  is  kept  moist  by  rains. 
Their  presence  shows  the  upward  tendency  of  the  feeding  roots  of  orange 
trees  when  left  to  grow  naturally  under  favorable  conditions. 

The  extent  to  which  the  root-systems  of  orange  trees  can  be  influenced 
by  orchard  treatment  seems  to  be  very  limited. 

The  deep-rooting  tendency  of  the  sour-orange  (plate  8)  is  observable 
in  both  light  and  heavy  soils,  while  the  roots  of  the  sweet-orange,  and 
in  a  lesser  degree  those  of  the  pomelo  (plates  6  and  7),  grow  near  the 
surface  in  all  kinds  of  soil  during  the  seasons  of  their  most  rapid 
growth,  and  the  only  way  in  which  they  can  be  forced  to  a  lower  depth 
is  to  plow  deeply  and  apply  irrigation  water  as  low  as  practicable.  As 
orchardists  can  not  with  present  facilities  afford  to  plow  deeper  than 
ten  or  twelve  inches,  the  fibrous  roots  will  mostly  be  found  just  below 
that  depth.  Even  after  trees  become  old  and  well  established,  their 
fibrous  roots  continually  seek  the  surface  soil,  unless  deep  plowing  and 
deep  irrigation  are  persistently  practiced.  One  orchard  near  Pomona, 
which  has  been  plowed  deeply  from  the  time  it  was  planted  and  irrigated 
in  deep  furrows,  bore  four  and  a  half  boxes  of  fruit  per  tree  at  the  age  of 
eleven  years.  An  adjoining  orchard  that  was  never  plowed,  but  was 
cultivated  frequently  and  irrigated  in  furrows  made  with  a  "  bull- 
tongue"  attachment,  produced  but  three  and  a  half  boxes  of  poorer 
oranges  at  the  same  age.  The  former  orchard  is  budded  on  sour-stock, 
which,  as  heretofore  shown,  roots  deeply,  and  it  received  a  liberal  amount 
of  fertilizers;  while  the  latter  orchard  is  budded  on  the  shallow-rooting 

3— Bul.  138 


—  34  — 

sweet-stock,  and  received  but  a  moderate  amount  of  fertilizers.  The 
more  productive  of  these  two  orchards  evidently  has  the  better  root- 
system;  it  has  also  been  plowed  deeply  and  irrigated  in  deep  furrows — 
therefore,  it  never  shows  the  need  of  water  before  the  regular  irrigation 
date  comes  around.  On  the  other  hand,  the  less  productive  orchard, 
which  is  on  surface-rooting  stock  and  has  received  much  shallower  cul- 
ture and  watering,  shows  signs  of  drought  before  each  irrigation  date. 
In  the  case  of  orchards  on  the  same  stock,  the  value  of  deep  plowing 
and  deep  irrigation  is  also  very  marked. 

The  So-Called  "Hardpan." — The  orange  tree  is  a  native  of  tropical 
forests,  where  it  obtains  warm  soil  and  abundant  moisture  within  easy 
reach.  Its  successful  culture  in  the  countries  like  California,  which 
lack  summer  rains  and  moisture-laden  atmosphere,  is  necessarily  to 
some  degree  artificial  and  a  notable  triumph  of  modern  horticulture. 
In  order  to  achieve  the  highest  results,  it  becomes  more  and  more  essen- 
tial that  the  grower  shall  keep  the  soil  in  the  most  perfect  condition, 
shall  apply  all  needed  water  and  plant-food  in  sufficient  but  not  in 
excessive  amounts,  and  shall  pay  especial  attention  to  keeping  the 
feeding  roots  as  low  as  practicable  and  to  preventing  the  formation  of 
what  is  called  " hardpan,"  but  is  only  the  well-known  "plow-sole," 
aggravated  by  shallow  irrigation. 

"Hardpan,"  some  growers  say,  appears  now  where  it  was  never  before 
known.  The  fibrous  roots  of  orange  trees  run  along  its  surface,  and 
thus  are  subject  to  every  vicissitude.  It  often  happens  that  what 
orchardists  call  "hardpan"  is  only  the  firm  layer  of  soil  caused  by 
uniform  cultivation,  or  plowing,  whether  deep  or  shallow.  The  depth 
to  which  soil  is  stirred  should  vary  from  year  to  year;  eight  inches, 
twelve  inches,  ten  inches,  fourteen  inches,  and  then  eight  inches  again, 
would  put  an  end  to  much  of  the  present  outcry  against  "  hardpan." 
Cultivator  teeth  should  also  be  kept  sharp  and  should  be  "  set  down" 
to  various  depths  so  as  to  prevent  the  formation  of  "  plow-sole"  of  any 
description,  and  to  assist  in  breaking  up  that  which  former  neglect  has 
caused. 

Very  few  orange  groves  have  been  planted  upon  true  "hardpan,"  and 
if  so  planted  have  seldom  succeeded.  Only  a  few  trees,  such  as  our 
native  oaks,  are  capable  of  thrusting  roots  through  the  iron-like  layer  of 
natural  subsoil  that  is  properly  termed  "hardpan."  When  found  to 
exist,  it  should  be  deemed  sufficient  to  debar  citrus  culture,  unless  so 
thin  that,  by  boring  or  blasting,  the  root-system  can  be  established  in 
good  soil  below  the  "hardpan,"  or  when  it  is  so  constituted  that  when 
kept  irrigated  the  roots  will  penetrate  it. 

An  instance  of  the  latter  occurred  at  Riverside,  where  Mr.  Reed 
planted  a  few  trees  on  a  terrace  bordering  on  an  arroyo,  and  found  what 


—  35  — 

was  reported  as  true  "hardpan"  near  the  surface.  The  trees  received 
"  an  abundance  of  water  over  the  whole  area  for  a  year,"  and  it  was 
then  found  that  the  roots  had  penetrated  it  to  a  considerable  distance. 

The  term  "irrigation  hardpan"  is  quite  generally  used  in  the  orange- 
growing  district  to  describe  the  condition  of  some  small  areas  in  orchards 
where  irrigation  and  subsequent  culture  have  been  careless,  or  where 
sufficient  attention  has  not  been  paid  to  the  difference  of  treatment 
required  by  lighter  and  heavier  soils. 

Of  course  very  sandy  soils  can  be  handled  sooner  after  irrigation  than 
can  heavier  soils,  and  when  a  sandy  piece  of  land  containing  areas  of 
heavy  soil  is  cultivated  as  soon  after  irrigation  as  the  sandiest  part  will 
permit,  trouble  may  be  expected  with  the  so-called  ''irrigation  hard- 
pan,"  by  the  puddling  of  the  subsoil,  partly  directly  by  the  plow, 
partly  by  the  soaking-in  of  clay-water. 

Value  of  Proper  Cultivation. — It  is  usual  for  orchardists  to  put  in  a 
subsoil  plow  to  help  in  breaking  up  the  heavy  spots  of  what  is  called 
"  irrigation  hardpan."  But  this  difficulty  can  easily  be  overcome  with- 
out using  a  subsoil  plow,  as  was  shown  by  the  experience  of  Mr.  W.  J. 
Cox,  of  Glendora,  Los  Angeles  County,  who  found  that  "irrigation 
hardpan  "  was  forming  in  a  part  of  his  orange  grove.  He  irrigated  a 
few  trees  that  were  within  reach  of  the  domestic  water-supply,  and  fol- 
lowed this  up  at  the  proper  time  with  thorough  cultivation.  After  each 
irrigation  he  cultivated  a  little  deeper.  As  a  result  of  deep  irrigation 
and  cultivation,  the  soil  took  in  water  as  readily  as  ever  and  the  trees 
regained  their  vigorous  appearance.  He  simply  used  a  chisel-tooth 
cultivator  and  plenty  of  water. 

A  somewhat  different  case  was  that  of  Mrs.  McKenzie,  of  Riverside, 
whose  orange  grove  failed  to  be  profitable,  though  apparently  well 
irrigated.  This  orchard  had  been  cultivated  to  the  same  depth  until  a 
hard,  clay  "plow-sole"  had  been  formed.  The  stratum  of  hard  subsoil 
was  several  inches  thick  and  contained  a  number  of  large  surface  roots. 
She  wrote  to  the  California  Experiment  Station,  sending  samples  of  soil 
for  examination.  It  was  found  that  the  plow-sole  prevented  the  irri- 
gation water  from  reaching  the  deeper  roots,  and  she  was  advised  to  plow 
the  entire  orchard,  roots  and  all,  as  deep  as  the  plow  would  go.  This 
was  done,  much  to  the  alarm  of  many  growers,  and  great  numbers  of 
orange  roots  of  all  sizes  were  turned  to  the  surface.  Following  further 
advice,  she  irrigated  and  cultivated  the  ground  deeply,  and  the  follow- 
ing season  she  harvested  the  largest  crop  ever  taken  from  this  grove. 

The  Glendora  grove,  to  which  allusion  has  been  made,  had  had  deep 
cultivation  from  the  beginning,  and  the  roots  were  mainly  below  the 
so-called  hardpan.  The  McKenzie  grove  had  many  roots  in  the  hard 
"plow-sole,"  so  that  the  only  remedy  was  to  destroy  these  useless  roots 
and  force  the  growth  of  new  and  deeper  ones,  at  the  same  time  giving 


—  36  — 

the  irrigation  water  a  chance  to  penetrate.  This  rather  drastic  root- 
pruning  was  necessary,  and  if  the  Glendora  grove  had  been  cultivated 
to  a  uniform  depth  a  few  more  seasons,  deeper  plowing  and  the  destruc- 
tion of  the  surface  roots  would  have  become  inevitable  there  also.  The 
breaking-up  of  all  hard  layers  of  soil  caused  by  improper  cultivation  or 
careless  use  of  water  is  of  the  first  importance  to  the  health  and  profit 
of  an  orchard. 

Reckless  Deep  Cultivation. — After  Mrs.  McKenzie's  experiment  at 
Riverside,  previously  mentioned,  subsoilers  of  different  forms  were  used, 
and  the  idea  soon  became  common  among  growers  that  the  deeper  a 
plow  could  be  run,  the  better  would  be  the  results  that  would  follow. 
The  injurious  results  of  such  practice  can  not  be  estimated  without 
careful  study  of  the  root-systems  of  orange  trees  on  various  stocks  and 
soils.  A  number  of  bearing  citrus  groves  were  so  much  injured  by  the 
reckless  use  of  subsoil  plows  that  the  leaves  of  the  trees  actually  wilted 
down  immediately  after  the  operation.  In  these  cases,  the  sharp-cutting 
plow  was  run  close  to  and  on  all  sides  of  the  trees.  When  trees  over 
ten  years  of  age,  which  have  been  subjected  to  uniform  shallow  plowing 
and  irrigation,  are  submitted  to  such  treatment,  they  probably  lose  at 
One  blow  not  less  than  seventy-five  per  cent  of  their  active  roots.  The 
shock  is  such  that  it  would  take  several  years  of  careful  treatment  to 
restore  the  trees. 

Practical  Notes  on  Deep  Cultivation  and  Irrigation. — It  is  almost  always 
more  economical  to  use  a  subsoiler  or  plow  where  "irrigation  hardpan" 
has  been  formed  than  it  is  to  use  the  large  amount  of  water  necessary  to 
soften  it;  but  according  to  the  best  practice  the  deepening  of  cultivation 
should  be  gradual,  and  the  implement  should  never  run  deeper  than 
fifteen  inches.  One  must  remember  that  the  really  serious  loss  in  sudden 
deep  cultivation  comes  from  the  destruction  of  thousands  of  fibrous  roots 
that  grow  from  the  hundreds  of  laterals  branching  from  the  large  main 
roots. 

If  a  plow  is  run  to  a  depth  of  one  foot,  in  three  furrows,  between  the 
rows,  and  water  percolates  slowly  for  a  long  time  through  these  furrows, 
no  need  can  arise  for  a  subsoiler.  "Irrigation  hardpan  "  within  reach 
of  the  plow  simply  shows,  as  has  been  said,  that  too  shallow  and  too 
uniform  cultivation  has  been  practiced.  In  that  case  the  entire  surface 
should  be  thoroughly  broken  up,  and  irrigation  in  deep  furrows  after 
this  will  restore  the  proper  conditions. 

Experience  also  shows  that  when  the  water  is  slowly  run  in  deep  fur- 
rows for  a  long  time  and  the  greater  part  of  the  surface  is  kept  dry  and 
is  deeply  cultivated,  better  results  are  obtained  than  when  the  basin  or 
block  method,  or  even  the  shallow-furrow  plan,  is  used,  even  though 
they  are  followed   by  deep  cultivation.     When   the   water   is    applied 


—  37  — 

below  the  first  foot  of  soil,  and  the  soil  above  is  kept  comparatively  dry, 
there  is  nothing  to  attract  the  roots  to  the  surface;  and  when  the  water 
is  thus  applied,  a  team  can  be  driven  along  the  dry  strips  of  land 
between  the  furrows,  and  with  a  harrow  or  other  appliance  the  dry  soil 
can  be  dragged  into  the  wet  furrows,  to  lessen  the  evaporation,  immedi- 
ately after  the  irrigation  water  is  turned  off.  By  any  other  system,  it 
is  absolutely  necessary  to  wait  at  least  twelve  hours,  and  sometimes 
much  longer,  before  a  team  can  be  driven  over  the  ground.  Then,  too, 
when  a  soil  irrigated  by  these  more  wasteful  methods  has  been  cultivated, 
it  is  still  moist  near  the  top,  and  is  soon  filled  with  a  mass  of  new  roots 
so  close  to  the  surface  that  they  must  be  destroyed. 

Waste  from  Evaporation  of  Water. — Water  applied  to  the  soil  sinks 
and  spreads.  Some  of  it  is  being  taken  up  by  the  still  dry  soil  under- 
neath and  at  the  sides  long  after  the  last  drop  is  visible.  Some  of  it, 
too,  is  being  drawn  back  to  the  surface,  and  thence  evaporated  into  the 
warm  air.  Irrigation  after  sundown  has  some  distinct  advantages,  if 
the  water  can  be  handled.  Sub-irrigation  upon  soils  adapted  to  its  use 
is  the  ideal  system  of  applying  water,  and  greatly  lessens  waste.  Orange 
roots  will  not  enter  a  pipe-line  unless  it  is  full  of  water  all  the  time.  If 
the  pipe  is  on  a  grade  and  open  at  bottom  and  top  so  that  air  passes 
through  it,  there  will  never  be  trouble  from  orange  roots.  Valves,  once 
thought  necessary,  are  not  now  used.  The  high  cost  of  the  present 
sub-irrigation  systems  places  them  beyond  the  reach  of  most  orange- 
growers. 

Spread  of  Water  from  Deep  Furrows. — The  accompanying  diagrams 
(plate  21)  show  the  extent  to  which  water  from  fairly  deep  furrows 
penetrates  the  sandy  soil  and  the  heavy  loam  of  the  substation.  A 
moment's  study  of  them  will  convince  any  one  that  the  only  way  in 
which  to  lessen  waste  in  surface  irrigation  is  to  let  the  water  flow  slowly 
through  as  deep  and  narrow  furrows  as  practicable,  thus  making  a 
larger  cross-section  of  wet  soil,  even  narrower  at  the  surface  than  in  the 
chart,  and  checking  the  evaporation  by  filling  the  furrow  with  dry 
earth  and  by  cultivation  at  the  earliest  moment. 

Examining  these  suggestive  diagrams  of  soil-saturation,  let  us  first 
call  attention  to  the  three  showing  the  spread  and  descent  of  water  on 
the  heavier  soil.  Here  it  has  spread  much  more  slowly  and  to  a  less 
extent  than  in  the  case  of  the  adjacent  sandy  land.  Even  after  two 
days'  run  of  water  (of  twelve  hours  each)  and  seventy-two  hours  further 
delay  (see  No.  3),  the  total  sectional  area  of  saturation  is  hardly  more 
than  half  as  great,  covering  about  sixteen  square  feet,  as  against  about 
thirty  square  feet  on  the  lighter,  more  porous  soil  (see  No.  6).  A  still 
deeper  and  narrower  water  channel  is  highly  desirable  on  this  heavier 
soil.     Instead  of  eight  inches,  it  might  well  be  sixteen  or  eighteen,  which 


—  38 


would  make  the  cross-section,  No.  3,  nearly  a  foot  deeper,  and  narrower 
on  the  surface. 

The  cross-sections  on  the  sandy  soil  show  that  the  eight-inch  furrow 
is  practically  sufficient  to  carry  the  water  well  down  into  the  soil.  A 
deeper,  narrower  channel  even  here  will  result  in  economy  in  the  use  of 

Clay  Loam.  Sandy  Soil. 

JS.it      lit       0  lit       fcjt.  lit.     1ft.      0  lit.      2/t 


7Z  HOURS  AFTER  IRRIGATION 
PLATE  21.    Percolation   Experiments.    Spread   of  Water    from 
Deep  Furrows  in  Heavy  and  Light  Soils. 

water,  a  smaller  flow  producing  as  large  an  area  of  saturation  as  that 
shown  in  diagram  6,  with  less  surface.  These  two  sets  of  illustrations 
of  the  results  of  irrigation  in  furrows  on  different  soils,  under  conditions 
otherwise  practically  identical,  explain  and  enforce  the  entire  argument 
respecting  deep  irrigation  set  forth  in  this  bulletin,  and  long  and  earn- 
estly recommended  by  Professor  Hilgard. 


—  39 


NOTES  ON  DISEASES  OF  THE  ORANGE. 

Three  diseases  of  the  orange  tree  are  widely  known  in  California. 
First  in  importance  come  two  kinds  of  "  gummosis,"  or  "gum  disease," 
that  which  attacks  roots  and  trunks  just  above  the  surface  of  the  ground, 
and,  second,  that  which  is  called  "  scaly  bark"  gum  disease.  The  former 
has  existed  in  Southern  California  since  1875.  It  makes  its  appearance 
where  the  ground  has  been  allowed  to  remain  wet  close  to  the  trees  for 
long  periods.  E.  W.  Holmes,  of  Riverside,  says  that  he  has  seen  fifteen 
per  cent  of  a  seedling  orange  orchard  become  affected  after  heavy  appli- 
cations of  nitrogenous  manures  followed  by  irrigation  close  to  the  trees 
during  hot  weather.  All  the  affected  parts  should  be  cut  out  so  as  to 
remove  every  trace  of  diseased  tissue.  In  some  cases  this  requires 
repeated  cuttings  and  the  use  of  an  antiseptic  wash. 

The  "  scaly  bark"  gum  disease  is  the  most  prevalent  form  in  South- 
ern California.     It  attacks  the  trunk  of  the  tree,  and  also  some  of  the 


a  b 

PLATE  22.    Gum  Disease  of  the  Orange  Wood. 
a.  No  disease,    b.  Darkening  of  wood  by  disease. 

branches.  If  not  checked  at  once  it  will  kill  the  tree.  The  new  bark 
is  unhealthy,  and  the  disease  soon  penetrates  to  the  center  of  the  limb 
or  the  trunk  of  the  tree.     (See  b,  plate  22.) 

Antiseptic  Washes  for  Gummosis. — The  treatment  for  both  forms  of 
gum  disease  is  the  same.  Use  one  part  of  crude  carbolic  acid  to  four 
parts  of  water.  The  Florida  Experiment  Station  uses  a  wash  of  lime, 
crude  carbolic  acid,  and  salt.  Slack  one  peck  of  lime  in  two  gallons 
of  water,  and  add,  of  crude  carbolic  acid  four  ounces,  and  of  salt  three 
pounds.     If  too  thick,  add  a  little  more  water. 

In  cases  of  the  root  form  of  gummosis,  the  soil  should  not  be  thrown 
back  upon  the  roots  after  cutting  out  the  diseased  tissue,  until  the 
wounds  begin  to  heal.     It  is  necessary,  however,  to  shade  the  roots  from 


—  40  — 

the  sun.     The  diseased  wood  should  be  burned.     Removal  of  the  entire 
tree  is  often  wiser  than  trying  to  cure  the  disease. 

Value  of  Sour-Orange  and  Pomelo  Stocks. — The  ''scaly  bark"  form  of 
gum  disease  has  not  been  observed  in  California  on  the  Florida  sour- 
orange  stocks.  Such  trees,  budded  to  Navel  oranges  two  feet  or  more 
from  the  ground,  are  growing  near  the  substation.  Some  of  them  have 
diseased  trunks  and  branches,  but  in  no  case  has  the  disease  been 
found  extending  down  to  the  sour-stock.  Evidently  there  would  be  no 
advantage  in  using  this  resistant  stock  in  low-budded  nursery  trees, 
but  sour-stocks  might  be  planted  in  the  orchard  and  allowed  to  form 
the  main  branches  of  the  future  tree.  Then  should  the  "  scaly  bark  " 
make  its  appearance,  a  few  branches  might  be  destroyed,  but  the  trunk 
would  remain  sound.  Since  the  sour-stock  has  not  given  universal 
satisfaction  in  Southern  California,  the  pomelo,  which  seems  but  little 
less  resistant  to  "scaly  bark"  than  is  the  sour-orange,  and  is  a  more 
universally  vigorous  grower,  may  be  used.  The  sweet-orange  stock  is 
the  poorest  of  the  three. 

The  " Die-Back"  Trouble. — The  third  serious  trouble  is  exanthema, 
or  "die-back."  This  name  is  given  to  a  weakness  affecting  orange, 
lemon,  and  other  orchard  trees.  There  are  several  especially  bad  cases 
in  the  San  Gabriel  Valley,  where  solid  blocks  of  citrus  trees  are  now 
utterly  worthless.  Trees  seven  years  old  and  in  a  frostless  location 
have  not  attained  a  height  of  over  four  feet,  in  some  instances,  and  bear 
little  or  no  fruit,  while  adjoining  trees  of  the  same  age  and  seemingly 
under  similar  conditions  are  of  large  size  and  bear  heavy  crops. 

Orange  trees  affected  with  u die-back"  make  an  apparently  healthy 
growth  in  the  spring  and  early  summer,  but  the  young  shoots  soon  turn 
yellow,  the  leaves  drop  off  and  the  twigs  die  back  to  the  older  wood, 
from  which  a  brown  granular  substance  exudes.  In  a  season  or  two, 
this  older  wood  also  dies.  Adventitious  buds  keep  developing  at  the 
axils  of  the  leaves,  until  at  the  end  of  the  season  there  are  small  knots, 
where  there  should  be  healthy  lateral  branches.  (See  plate  23.)  Ex- 
periments with  Bordeaux  mixture  and  carbonate  of  copper  have  been 
made  in  a  badly  affected  grove  near  Pomona.  The  work  so  far  has 
shown  no  appreciable  results,  but  it  has  not  yet  been  carried  through 
one  season. 

[In  almost  all  cases  of  "die-back,"  examination  has  shown  some 
fault  in  the  subsoil,  which  puts  the  roots  under  stress.  Such  fault  may 
be  an  underlying  hardpan  or  impervious  clay,  pure  and  simple;  or  it 
may  be  excessive  wetness  or  dryness  of  the  substrata  surrounding  the 
deeper  roots;  or  the  rise  of  bottom  water  from  below,  as  in  cases  of  over- 
irrigation.  The  true  "die-back"  is  not  properly  a  disease,  but  simply 
the  manifestation  of  the  distress  felt  by  the  root-system  underground. 


—  41  — 

The  first  thing  needful  is  to  dig  down  and  examine  the  roots,  and  then 
to  relieve  whatever  fault  may  be  found,  if  possible;  which  may  not 
always  be  the  case.  Sometimes  an  appearance  similar  to  the  "  die- 
back"  is  caused  by  the  roots  encountering  a  marly  stratum,  which  is 
apt  to  stunt  the  growth  of  the  tree,  causing  it  to  put  out  a  multitude  of 
small,  thin  branches,  and  sometimes  causing  the  tips  to  die  ofT.  For 
this  form  of  the  trouble  there  is  no  permanent  remedy;  the  trees  should 


PLATE  23.    "Die-back"  of  Orange  Limbs. 

never  have  been  planted  in  such  ground,  any  more  than  in  such  as  has 
shallow-lying  hardpan  or  clay.     (E.  W.  H.)] 

["Mottled  Leaf." — Closely  related  in  its  causes  to  the  "die-back,"  and 
sometimes  accompanying  it,  is  the  "mottled  leaf"  trouble.  It  may  be 
properly  called  "partial  chlorosis"  of  the  leaves,  and  on  the  basis  of 
that  designation  it  has  been  attempted  to  treat  it  like  the  correspond- 
ing human  ailment,  with  iron  tonics  and  fertilizers.  But  in  every  case 
that  I  have  closely  examined,  and  in  most  of  those  reported  to  me  by 
others  who  have  made  such  examinations  at  my  suggestion,  the  cause 


—  42  — 

was  not  lack  of  nourishment  that  could  be  remedied  by  such  means, 
but  simply  an  improper  condition  of  the  root-system,  especially  of  the 
deeper  roots.  When  a  thriftily  growing  tree  suddenly  stops  and  begins 
to  show  mottled  leaves,  it  is  clearly  not  because  of  lack  of  nourishment 
in  the  soil,  but  because  some  of  the  physical  requirements  of  the  tree's 
well-being  have  ceased  to  be  satisfied.  In  such  case  fertilization  can 
afford  but  temporary  relief,  if  any. 

The  commonest  cause  of  mottled  leaf  is  a  layer  of  dry  gravel  or  sand 
reached  by  the  tap-roots,  throwing  them  out  of  healthy  action.  Of 
course  the  same  effect  may  be  expected  from  the  exhaustion  of  the 
usual  supply  of  moisture  in  the  substrata,  which  has  not  been  made  up 
for  by  the  comparatively  scanty  irrigation  permitted  by  the  diminished 
water-supply  during  the  past  three  years.  The  cause  of  the  present 
great  prevalence  of  mottled  or  yellow  leaf  in  the  citrus  orchards  is 
probably  a  parallel  to  the  wholesale  dying-out  of  vineyards  in  the 
Santa  Clara  Valley,  regarding  which  a  special  bulletin  (No.  134)  was 
issued  by  this  Station  some  months  ago. 

Quite  probably,  however,  other  unfavorable  conditions  affecting  the 
roots,  such  as  alkali,  marl,  or  a  hardpan  layer,  may  in  many  cases 
produce  this  effect.  In  any  case,  the  cause  should  be  sought  for  at  the 
roots  before  deciding  upon  possible  remedies.     (E.  W.  H.)] 

Difficulty  of  Replacing  Trees. — It  is  difficult  to  install  new  trees  in  an 
orchard  when  the  surrounding  trees  are  large.  In  fact,  it  is  necessary 
to  dig  very  large  holes  and  fill  them  with  rich  earth.  Such  trees  should 
be  given  extra  irrigation  and  additional  fertilizers,  besides  what  is  regu- 
larly given  to  the  older  trees.  This  should  not  be  applied  merely  to  the 
space  around  the  newly-set  trees,  but  also  to  the  adjoining  older  trees, 
as  it  is  needful  to  furnish  enough  food  and  water  for  all  the  roots  that 
fill  the  surrounding  soil. 

All  orchardists  find  trouble  in  filling  gaps  where  trees  have  died  or 
become  diseased,  but  the  difficulties  are  more  marked  in  the  case  of 
citrus  fruits  than  with  the  deeper-rooting  deciduous  species.  A  selection 
of  especially  healthy  specimens  from  the  nursery  will  help.  Then,  as 
noted,  the  best  of  culture  and  all  the  fertilizers  that  can  be  assimilated 
are  needed.  Lastly,  the  judicious  root-pruning  of  large  adjacent  trees 
may  assist  those  newly  planted. 

CALIFORNIA  ORANGE  AND  LEMON  STANDARDS. 

Citrus-fruit  culture  includes  much  that  can  find  no  place  in  so  brief  a 
bulletin,  but  some  of  the  more  pressing  and  practical  problems  have 
been  discussed.  The  interesting  topic  of  wind-breaks  and  hedges  for 
protection  against  frost  and  storms  has  not  been  taken  up,  nor  has  the 
group   of  questions  relating  to  the  handling  and  marketing  of   crops. 

But  there  is  often  an  inquiry  made  respecting  the  official  scale  used 


—  43  — 

by  judges  of  citrus  fruits  at  fairs  and  other  competitions.  A  standard 
scale  of  points  is  that  adopted  by  the  Los  Angeles  Chamber  of  Com- 
merce in  1894  and  the  following  year  by  the  Southern  California  Fruit 
Exchange.  It  seems  well  balanced,  comprehensive,  and  practical.  At 
the  present  time  it  is  the  most  widely  used  official  scale  in  California. 

The  following  rules  have  been  adopted  by  the  executive  committee  of 
the  Los  Angeles  Chamber  of  Commerce  in  reference  to  the  judging  of 
citrus  fruits: 

No  person  shall  be  allowed  to  serve  as  judge  in  any  class  in  which  he 
is  an  exhibitor. 

Any  exhibitor  who  addresses  a  judge  while  the  latter  is  in  discharge 
of  his  duty,  will  be  debarred  from  competition. 

A  majority  of  the  judges  present  shall  constitute  a  quorum  for 
decision  in  any  class. 

Preliminary  Classification. — Season:  Early,  from  December  to  April; 
middle,  February  to  July;  late,  June  to  December. 

Size:  Large;  medium;  small. 

(The  managing  committee  from  each  competing  state  or  section  is  to 
nominate  varieties  to  any  or  all  of  the  above  classes,  with  months,  and, 
when  practicable,  days,  for  tests  of  its  own  fruit.  Fruit  to  be  judged  by 
standards  of  its  class.  So  far  as  practicable,  no  committee  is  to  judge 
fruit  of  more  than  one  size,  as  per  above  classification.) 

ORANGE    SCALE    TO    BE    USED. 

Divisions  of  scale:  Size,  form,  color,  weight,  peel,  fiber,  grain,  seed, 
taste;  to  be  considered  in  order  named.  Credits  to  be  units  and  tenths 
thereof,  to  be  expressed  decimally;  possible  total  to  equal  100. 

1.  Size.     Possible  credits,  10. 

Large,         126's,  3-f    inches  in  diameter. 

a.      ,      ,        Medium,     176's,  2£4 

Standards:  i        *  '     lb 

j  Small,         250  s,  zy-g- 

L  Tangerines,  etc.,  2-g 
One  unit  discount  for  each  -J  inch  deficiency  or  excess  in  any  size. 

2.  Form.     Possible  credits,  5. 
Standards:  Round,  oval,  ovate,  pyriform. 

Discount  for  lack  of  symmetry  and  for  form  blemishes.  Navel  marks 
not  to  be  discounted,  except  when  of  abnormal  size  or  bad  form. 

3.  Color.  Possible  credits,  19,  divided  as  follows:  Bloom,  2;  peel,  10; 
flesh,  7. 

Standards:  Bloom  to  be  perceptible,  and  to  be  discounted  according 
to  degree  of  deficiency  or  of  injury  thereto;    peel  to  be  of  rich,  deep 


a 

u 

a 

a 

a 

a 

a 

a 

a 

—  44  — 

orange  color,  in  natural  condition,  and  to  be  discounted  according  to 
degree  of  deviation  therefrom,  one  or  more  points;  rust^  scale,  and  smut 
to  be  discounted  five  to  ten  points,  and  fruit  that  gives  visible  evidence 
of  having  been  cleaned  of  the  same  to  be  subject  to  equal  penalty;  also 
peel  that  has  been  rubbed  or  "  polished,"  giving  a  gloss  at  the  expense 
of  breaking  or  pressing  the  oil-cells,  to  suffer  same  discount.  Flesh  to 
be  rich,  clear,  and  uniform,  in  any  of  the  shades  common  to  fine  fruit. 
(Omit  consideration  of  "flesh  color"  until  after  concluding  division  5, 
"peel.") 

4.  Weight.     Possible  credits,  10. 

Standards:  Specific  gravity,  1,  with  buoyancy  of  j  oz.  allowed  to 
"large"  fruit,  \  oz.  to  "medium,"  and  \  oz.  to  "small,"  all  without 
discount. 

One  point  to  be  discounted  for  first  half-ounce  of  buoyancy  in  excess 
of  allowance,  and  thereafter  two  points  for  each  additional  half-ounce. 
(Note. — Buoyancy  may  be  easily  determined  by  clasping  weights  to  the 
fruits  with  light  rubber  bands,  and  then  placing  in  water.) 

5.  Peel.  Possible  credits,  10,  divided  as  follows:  Finish,  3;  pro- 
tective quality,  7. 

Standards:  Of  finish,  smoothness  and  uniformity  of  surface,  and 
pleasant  touch;  of  protective  quality,  firm  and  elastic  texture, 
abundant,  compact,  and  unbroken  oil-cells;  and  -g-  to  T8^  inch  thickness. 

Discount  one  half  point  for  first  ^  inch  above  maximum  or  below 
minimum,  and  two  points  for  second  -fa  inch,  provided  that  to  long- 
picked  and  fully-cured  oranges  the  minimum  shall  be  lowered  to  -%%  inch; 
and  that  to  fresh-picked  and  to  slightly-cured  "large"  fruit  the  maxi- 
mum shall  be  raised  to  £  inch. 

Breaking  of  oil-cells,  breaking  of  peel  and  abrasions  of  same  to  be 
subject  to  one  to  ten  discounts,  according  to  degree. 

(Here  consider  "Color  of  Flesh" — see  division  3.) 

6.  Fiber.     Possible  credits,  8. 

Standards:  Septa  delicate  and  translucent;  maximum  diameter  of 
core,  T3g-  inch  in  "large"  fruit  and  ^  inch  in  other. 

7.  Grain.     Possible  credits,  4. 
Standards:  Fineness,  firmness,  compactness. 

8.  Seed.     Possible  credits,  4. 
Standard:  Absence  of  seed. 

Discount  one  point  for  each  seed.  Each  rudiment  to  be  considered 
as  a  seed  if  any  growth  has  been  developed;  otherwise  allowed  without 
discount. 


—  45  — 

9.  Taste.  Possible  credits,  30,  divided  as  follows:  Sweetness,  15; 
citrous  quality,  15. 

Standards:  Clearness  and  definability  of  elements;  sweetness  rich, 
delicate  rather  than  heavy;  citrous  quality,  pronounced. 

Deficiency  or  absence  to  be  cause  for  discounts  against  any  element, 
and  excess  to  be  like  cause  against  sweetness,  and  against  acid  in 
"  citrous  quality," 

Staleness  and  flavors  of  age  or  decay  to  be  discounted  from  aggregate 
of  points  in  this  division. 

LEMON    SCALE. 

Divisions:  Size,  form,  color,  weight,  peel,  fiber,  grain,  seed,  taste. 
Rules  of  counts  and   discounts   as  in   scale  for   oranges.     Total  of 
possible  credits,  100. 

1.  Size.     Possible  credits,  10. 

{Large,      250's,  2§  inches  in  diameter. 
Medium,  300's,  2^       "       "         " 
Small,      360's,  1£       "       " 
All  sizes  between  250's  and  360's  allowed. 

Larger  fruit  to  be  discounted  one  point  for  each  J  inch  in  excess. 
Smaller  to  be  discounted  one  point  for  400's  (If  inches)  and  four  points 
for  450's  (1-|  inches). 

2.  Form.     Possible  credits,  5. 

Standard:  Oblong,  with  allowance  of  well-formed  points  at  stem  and 
tip.     Symmetry  required. 

3.  Color.     Possible  credits,  15. 
Standard:  Bright,  clear  lemon. 

Discounts  according  to  degree  for  green  splashes,  dashes  of  bronze,  or 
deep  shades,  or  for  sunburn. 

Rust,  scale,  and  smut,  with  fruit  that  gives  evidence  of  having  been 
cleaned  of  the  same,  to  be  discounted  five  to  ten  counts. 

Rubbing  or  dusting,  if  heavy  enough  to  press  oil  from  the  cells,  to  be 
causes  for  discount. 

4.  Weight.     Possible  credits,  10. 

Standard:  Specific  gravity,  1  (equal  to  that  of  water),  with  buoyancy 
of  i  oz.  allowed  to  "  large "  lemons  and  J  oz.  to  "  medium "  and 
"  small,"  all  without  discount. 

One  point  to  be  discounted  for  first  \  oz.  excess  of  allowance,  and  two 
points  for  each  \  oz.  thereafter. 


—  46  — 

5.  Peel.  Possible  credits,  10;  subdivisions  of  which  are:  Finish,  3 
credits;  protective  quality,  7  credits. 

Standard:  For  protective  quality,  to  be  strong,  elastic,  and  reasonably 
firm  texture;  abundant,  compact,  and  unbroken  oil-cells;  and  thickness 
of  -^  to  T3g-  inch. 

To  be  discounted  two  counts  for  first  -$■%  inch  below  minimum,  and 
five  counts  for  second  ^  inch;  one  count  for  first  ^  inch  above  maxi- 
mum, and  two  for  each  succeeding  ■£%  inch. 

Fresh-picked  lemons  not  allowed. 

6.  Fiber.     Possible  credits,  8. 

Standard:  Septa  delicate  and  translucent.  Core  not  to  exceed  T3g- 
inch  in  "large"  and  i  inch  in  "medium"  and  "small"  fruit. 

7.  Grain.  Possible  credits,  8,  divided  as  follows:  Fineness,  firmness, 
and  compactness,  4  credits;  color,  4  credits. 

Standard:  Grain  to  be  water-colored,  shading  to  blue  rather  than  to 
gray. 

8.  Seed.     Possible  credits,  4. 
Standard:  Absence  of  seed. 

One  half  point  to  be  discounted  for  each  seed.  (A  discount  of  i 
credit  for  each  seed  is  now  recommended  as  sufficient.) 

Rudiments  are  to  be  considered  as  seed  if  any  growth  has  been 
developed;  otherwise  allowed  without  discount. 

9.  Taste.  Possible  credits,  30,  divided  as  follows:  Acidity,  20  credits; 
absence  of  bitterness,  10  credits. 

In  interstate  competitions  the  standard  of  acidity  shall  be  the  high- 
est per  cent  of  strength  of  acid  found  in  any  fruit,  determined  by 
chemical  test.  In  other  competitions  such  tests  may  be  applied  as 
committees  or  competitors  may  require. 

Bitterness  to  be  determined  by  slicing  fruit  (including  peel)  thin, 
covering  with  hot  water,  and  cooling  slowly;  to  stand  twenty-four 
hours  when  practicable  (no  sugar  to  be  used).  Should  a  trace  of  bitter- 
ness appear  to  the  taste,  discount  one  point;  should  the  bitterness  be 
fairly  defined,  discount  two  points;  if  pronounced,  discount  five  points; 
and  if  strong,  ten  points. 


